The answer is C. Why it’s C is because it’s describing two things which would need a comma between
Answer and Explanation:
One lesson Twain learns as a cub pilot is to trust himself. As an apprentice, he works under Mr. Bixby. Upon being given the chance to navigate on his own, Twain is initially very confident in his own skills. However, Mr. Bixby asks him if he is really sure he can do it. Twain grows immediately insecure. He doubts himself, even though he truly knows what to do. It was all a test. Bixby wanted to teach him a lesson: to never doubt his own skills because of what others say.
