While we expected it to be gradual, the process of transition to civilian rule came to an … end.

Analyze the question: The underlined word is "gradual" (the underline isn't visible here, but "gradual" is clearly the target, since the sentence says "we expected it to be gradual"). We need a word that:

1. Is opposite in meaning to "gradual"
2. Fits the gap in "came to an ........ end"

Concept: "Gradual" means happening slowly, step by step, over time. Its opposite describes something sudden or quick.

Checking each option:

• A. abrupt means sudden and unexpected. It is the opposite of gradual, and "came to an abrupt end" is a very common phrase. ✔
• B. anticipated means expected. It does not oppose "gradual" (a gradual process can be anticipated), and the sentence contrasts with what was expected. ✘
• C. unhappy is about emotion, not speed or manner. ✘
• D. unpleasant is also unrelated to speed. ✘

Solution: The sentence says "While we expected it to be gradual..." and the word "While" signals contrast. The transition was not slow and steady, but sudden. So "came to an abrupt end" fits both the meaning and the grammar.

Answer: A. abrupt

Tip: In these "opposite + gap" questions, check two things: (1) the word must be an antonym of the underlined word, and (2) it must make sense in the sentence. Contrast words such as "while," "but," and "although" are clues that the missing word opposes an earlier idea. Also memorize common antonym pairs: gradual ↔ abrupt/sudden, scarce ↔ abundant, ancient ↔ modern.