One of the most important things I've learned is how much there is to learn, and how much I don't yet know.()

A. ...that in the vast sea of knowledge I'm just a little drop.
B. ...that I know very little and there's much for me to learn.
C. ...that I am ignorant, so I must learn what I do not know.
D. ...that compared with what I don't know, my knowledge is limited.