Question

choose the answer that best completes the sentence below. u.s. forces invaded the nation of afghanistan, searching for osama bin laden ________ he was the leader of the network that organized the attacks. a therefore b although c in contrast d because

Explanation:

The second part of the sentence gives the reason for the first part. "Because" is used to introduce a reason. "Therefore" shows a result, "although" shows a contrast, and "in contrast" is also for showing a contrast.

Answer:

D. because