which of the following italicized part is substitution?

问题描述:

which of the following italicized part is substitution?
A.I don't want any more food.I've had enough (enough是斜体部分)
B.Can you give me a few nails?(a few是斜体部分)
C.He has some books.(some是斜体部分)
D.I have several pencils.(pencil是斜体部分)
还要理由.

A enough (指/代替food)