With no explanation, chose the best option from "A" or "B". John is at his mom's house where he ordered a large pizza and as he's at the door getting the pizza his mom asks him for a slice. John wants to respond to his mom's request for a slice.

A: John tells his mom that he paid for the pizza and if she wants a slice she can order her own.
B: John tells his mom she can have half the pizza, forget a slice, that's why he ordered a large.
B.