What lesson dose Mr. Bixby try to teach the narrator in A Cub Pilot

This question is incomplete. I've found the complete question online. It is the following:

What lesson does Mr. Bixby try to teach the narrator in “A Cub Pilot”?

A. to know when he is being tricked

B. not to be so certain of his own abilities

C. not to rely on his existing knowledge

D. to keep a cool head in tense situations

The lesson Mr. Bixby tries to teach the narrator is:

D. to keep a cool head in tense situations

Explanation:

In Mark Twain's "A Cub Pilot", Mr. Bixby shakes Samuel's confidence on purpose. He makes Samuel doubt his own abilities, second-guess himself. All Mr. Bixby does is ask Samuel if he is sure he can navigate on his own. Later on, however, he tells Samuel he shouldn't allow him (Mr. Bixby) nor anyone else to shake his faith in himself. He (Samuel) should keep a cool head in tense situations, no matter what it is that people tell him.

thunder! imagine dragons

i decided to stay late in the laboratory to continue my experiment with the lightbulb. at midnight, thomas edison opened the door and saw all the stuff he was working on. the lightbulb, film and the transmitter. as he walks in an idea hits him on how the lightbulb would work. he would have to change a few wires around to get it to light up. when he did change the wires around it worked so he decided to write a telegraph to his friend to tell him about his success.   as he was packing up he grabbed the telegraph and walked to his home. he told his wife about the success and the next morning mailed the telegraph.