The passage lists what went wrong with the earlier Aichi Targets, mass extinction risk and unmet goals, as background, but the actual worry it raises about the new GBF is different: because the GBF depends on broad systemic policy change with "no plan B," researchers want a single clearly defined target so the goal is obvious to both the public and policymakers.
Options (A), (C) and (D) all describe the past plan's shortcomings or the general extinction crisis, not a problem with implementing the GBF itself.
Option (B) is the one point the passage actually ties to the GBF's own success going forward, the absence of one clear, easily communicated target.
The correct answer is clarity of action plan for the society and government.
The question is about the researchers' reasoning for wanting a single biodiversity target prioritised within the post-2020 GBF. Let's go through the options.
The reasoning that fits the researchers' position is the difficulty of implementing systemic policy change under a diffuse, multi-target framework.
So, the correct answer is Systemic policy change is difficult to implement.
Here we need the option that expresses the author's own opinion on the post-2020 GBF, not a neutral fact or a suggestion.
The correct answer is Implementation of the post-2020 Global Biodiversity Framework (GBF) allows no middle ground for success or failure.
Central theme questions ask for the idea that runs through the entire passage, not a single supporting fact. Let's rule out the options one by one.
So, the correct answer is The future of biodiversity conservation efforts at global level.
An inference question wants the conclusion the discussion points to, without stating it directly. Let's test each option.
The correct answer is The holistic nature of the post-2020 Global Biodiversity Framework (GBF) can be a boon or a bane.