Johnny Has Two Mini-Doughnuts and His Sister Has Two Full-Sized

Johnny has two mini-doughnuts and his sister has two full-sized doughnuts. If Johnny understands that he and his sister have the same number of doughnuts, even though hers are bigger, then he

A) knows that numbers are an amount.
B) knows that number words refer to specific quantities.
C) knows that the size of entities isn't relevant to quantity.
D) knows that numbers are ordered from smallest to largest in quantity.