Answer:
(D) Despite his nerves, he was ready for his first interview; he had thought through each potential question.
Explanation:
Semicolons are used when dealing with two thoughts that could be their own sentences.
Potential Sentence One: Despite his nerves, he was ready for his first interview.
Potential Sentence Two: He had thought through each potential question.
The semicolon separates these two sentences, so that they are one sentence.
<u><em>Despite his nerves, he was ready for his first interview; he had thought through each potential question.</em></u>
