The fastest way to find a passage's central idea among four options is to check which option every paragraph can be filed under, and rule out options that only cover one section.
"Fossil fuels in war-making" only covers the WWI/WWII paragraphs, not the later US-dominance paragraphs.
"Strategic value in US dominance" only covers the closing paragraphs, not the war history that comes before it.
"Distribution of fossil fuels" appears once, in the first line, and is never returned to.
"Role of fossil fuels in the modern geopolitical order," however, is broad enough to hold the wars, Britain's historical role, and the US's present strategy all under one umbrella, nothing in the passage falls outside it.
Since only one option survives this paragraph-by-paragraph check, the correct answer is Role of fossil fuels in modern geopolitical order.
For "cause" questions with an "All the above" option, check whether the listed causes are really links in one chain rather than independent, competing reasons.
Here they are clearly one chain: Germany lacked oil, which is why Britain and France's oil supply gave them a comparative advantage, which is why Germany's coal-burning navy (needing to refuel every eleven days) could not be used effectively despite its size.
Each statement follows directly from the one before it in the passage's own explanation, so removing any one of them would break the causal chain the passage describes.
Because the shortage, the Allied advantage, and the naval weakness are all presented together as one connected explanation, the correct answer is All the above.
When a question asks what can be "inferred" from a specific person's opinion, stick closely to what that person actually described, and don't borrow ideas from a different part of the passage attributed to someone else.
Klare's own words describe the US military functioning as "a global oil protection service, guarding pipelines, refineries, and loading facilities." That is a description of military force being used as a tool of energy policy, in other words, energy policy carried out through militarized means.
"Interferes with energy needs" (Option A) overstates this into obstruction, when Klare describes protection, not disruption. "Changed drastically" (Option C) and "fully understood the strategic value" (Option D) both pull in ideas from other parts of the passage that are not part of Klare's specific statement.
Staying strictly within what Klare's quote supports points to The US energy policy has become increasingly militarized.
Break the word down: "tangential" shares its root with "tangent," a line in geometry that touches a circle at exactly one point and then moves away, rather than running through it. That single, glancing point of contact is the whole idea behind the word.
Applied to the sentence, saying the strategic value of oil is "tangentially related" to US energy needs means the two touch only slightly, not that they're tightly bound together. That is confirmed by the very next lines of the passage, which say the US became self-sufficient in fossil fuels WITHOUT this reducing the strategic importance of controlling oil flows, showing the two really are only loosely, incidentally connected.
This rules out "direct" and "central" (both opposite in meaning), leaving Related only slightly and peripherally as the correct answer.
On questions like this, watch out for options that are true statements from the passage but answer a slightly different question than the one being asked, the question here is specifically about WHY the US is a "strategically dominating global hegemon," not about what the US military does or how its policy is run.
The passage directly says the US's role as "guarantor of global energy flows... is still crucial to US strategic dominance and to its position as global hegemon," which is a near word-for-word match for option C.
Option A describes a specific action (guarding pipelines and refineries) that happened AFTER the Iraq War, a symptom of the hegemonic role rather than its source. Option B describes a trend in policy style (militarization), also a downstream feature, not the reason for hegemony itself.
Since only one option restates the passage's actual stated cause, "All the above" over-includes, and the correct answer is The role of US as a guarantor of global energy flows.