Which of the following passages best expresses mark twain's purpose in ''a cub pilot''?
a. he{a pilot} must have good and quick judgment and decision, and a cool, calm courage that no peril can shake.
b. your shouldn't have allowed me or anybody else to shake your confidence in that knowledge. try to remember that.
c. i had become a good steersman; so good, indeed, that i had all the work to do on our watch, night and day.
d. there 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 .