D) uniquely
The phrase in a unique manner is not parallel in this sentence. The author should change it to "uniquely" to make the word forms match ("vividly, honestly, and uniquely").
Answer:
Since all the options concern the word "unique", we may assume the underlined phrase is "in a unique manner". The best replacement for it is: D) uniquely.
Explanation:
None of the other options is plausible because:
- A is exactly the same phrase;
- B and C change the phrase's meaning.
However, even if we had more than one viable option, we must take the context into consideration before choosing.
The author of the sentence chose to use adverbs to describe the way Serena tried to portray her subjects. There are two adverbs ending in -ly before the phrase "in a unique manner" - vividly and honestly. Their presence creates parallelism, which is the repetition of a certain grammatical form inside the sentence. Parallel structures tend to sound better, so the best option would be to keep it. That's why letter D) uniquely would be the best replacement for the phrase. It would maintain the parallelism present in the structure.
- After finally taking up painting, Serena constantly strove to portray her subjects vividly, honestly, and uniquely.
