Which of the following passages best expresses Mark Twain's purpose in ''A Cub Pilot''?

AHe{a pilot} must have good and quick judgment and decision, and a cool, calm courage that no peril can shake.

BYour shouldn't have allowed me or anybody else to shake your confidence in that knowledge. Try to remember that.

CI had become a good steersman; so good, indeed, that I had all the work to do on our watch, night and day.

DThere is one faculty which a pilot must incessantly cultivate until he has brought it to absolute perfection. Nothing short of perfection will do. That faculty is memory .