Which one of these excerpts from Mark Twain's Life on the Mississippi best shows that the story is told in first person?

Which one of these excerpts from Mark Twain's Life on the Mississippi best shows that the story is told in first person?

A. Ten minutes later the steamer is under way again, with no flag on the jack-staff and no black smoke issuing from the chimneys.

B. I first wanted to be a cabin-boy, so that I could come out with a white apron on and shake a tablecloth over the side, where all my old comrades could see me.

C. Then such a scramble as there is to get aboard, and to get ashore, and to take in freight and to discharge freight, all at one and the same time.

D. Assembled there, the people fasten their eyes upon the coming boat as upon a wonder they are seeing for the first time.