Which detail from "A Cub Pilot" helps shape the central idea that if you believe in and trust yourself, no one should be able to shake your confidence?

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

Which detail from “A Cub Pilot” helps shape the central idea that if you believe in and trust yourself, no one should be able to shake your confidence?

A. Mr. Bixby asks, “Didn’t you know there was no bottom in that crossing?”

B. Twain says to Mr. Bixby the he can make the crossing “with [his] eyes shut.”

C. Mr. Bixby tells Twain, ““I am going below awhile.”

D. Twain tells Mr. Bixby that he couldn’t hit the bottom of the river “with a church steeple.”

The detail that shapes the central idea is:

A. Mr. Bixby asks, “Didn’t you know there was no bottom in that crossing?”

Explanation:

In Mark Twain's "A Cub Pilot", Mr. Bixby teaches Samuel a lesson about confidence and trusting oneself. At first, Samuel is sure of his abilities to navigate without Mr. Bixby. He even says he can do it with his eyes shut. Yet, when Mr. Bixby asks him if he is sure he can really do it, Samuel begins to doubt it. That one question was enough to make him second-guess himself. Even though he does know how to do it, he becomes unsure of his ability.

When Mr. Bixby asks, “Didn’t you know there was no bottom in that crossing?” he reveals it was a test. He wants Samuel to learn to not doubt his skills, even if others seem to doubt them.

answer: the correct answer is b. an essay that connects the writer's experience with a topic of significance and of reader interest.

explanation: the key words are here "personal experience" since personal essays give insights about peoples' experiences in life and introduce us in their unique world that can be or not to related to our lives but interests us because we are human beings and share the same condition universally.  

i dont know doing this for points