Answer:
D) The flower garden was vibrant, it was very lively!
Step-by-step explanation:
Let's go over the rest of the answers to see why they're wrong.
A) words like "rather" or "instead" indicate that two clauses or parts of a sentence contradict one another. so truculent and easygoing are antonyms.
B) it is true that to be truculent means to not give up easily, it's just not answering the question itself. "she didn't give up easily" is just defining the word, not using a synonym as a context clue.
C) "angry as a bear" is just an example of a simile. totally irrelevant.
D) is correct because vibrant and lively are synonyms, and the text uses one word to define another, therefore creating a relationship between the two words that mean the same thing.