Step 1: Understanding the Concept:
An antonym is a word that expresses the complete opposite meaning of another word.
"Optimistic" describes a psychological state or a mental disposition focused on positive outcomes.
To find the antonym, we must look for a word that describes a negative, dark, or cynical outlook on life or future events.
Step 2: Detailed Explanation:
The word "Optimistic" originates from the Latin {optimum}, meaning "the best."
An optimistic individual is someone who consistently expects the best possible result and maintains a high level of confidence in the face of uncertainty.
Let us analyze the emotional and semantic context of each provided option:
Option (A) "Cheerful" is a synonym-adjacent word. It describes an outward expression of happiness which often accompanies an optimistic outlook.
Option (B) "Positive" is a direct synonym. It refers to a constructive and confident attitude toward situations.
Option (C) "Hopeful" is another synonym. It implies a feeling of expectation and desire for a specific positive thing to happen.
Option (D) "Pessimistic" comes from the Latin root {pessimum}, which means "the worst."
A pessimistic person is the behavioral and psychological polar opposite of an optimistic person. They focus on the flaws, expect failure, and maintain a gloomy outlook on the future.
In standardized tests, "Optimism" and "Pessimism" are the standard pairing used to test the understanding of extreme binary opposites in human behavior.
Because "Pessimistic" describes the state of expecting the worst, it serves as the perfect antonym for "Optimistic."
Step 3: Final Answer:
The antonym of "Optimistic" is option (D).