为自己加油

Choose the closest paraphrased version after the following sentence or the italicized part.

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.