Answer:
D. He thinks that he knows the river better than any of the pilots do.
“If anybody had questioned my ability to run any crossing between Cairo and New Orleans without help or instruction, I should have felt irreparably hurt.”
Explanation:
"Cub Pilot" is from the novel "Life On The Mississippi" by Mark Twain. It tells the experience of Samuel Clemens/ Mark Twain as a steersman under his chief Mr. Bixby.
When Mr. Bixby asked Mark to navigate the boat while he went below for a while, he felt confident of doing it without supervision. His confidence in his ability and knowledge is on the high and he felt sure of it. He thinks that there is no other pilot that knows the river better than him. This is supported by his admission "If anybody had questioned my ability to run any crossing between Cairo and New Orleans without help or instruction, I should have felt irreparably hurt."