The correct answer is A. During separate semesters
Step-by-step explanation:
In the sentence presented, the word "concurrent" that refers to the courses James decide to take means at the same time or simultaneously. This meaning is mainly suggested in the first clause "Rather than taking them during separate semesters" that states "concurrent" is exactly the opposite to taking courses in separate semesters and therefore this helps the reader to understand "concurrent" is simultaneous or during the same semester. Thus, the phrase that reveals the meaning of the word concurrent is "during separate semesters" as this acts as an antonym and suggesting the meaning of the word.