Articles (intermediate-4) fill in the blanks

 a / an / the / -

A: Would you like apple?

B: Oh, yes please! I love apples.

A: Well, there's big one and small one.

B: Oh, I'll have small one please.

A: Are you sure you won't have big one.

B: No, thanks. Mmmm! what delicious apple!

A: Glad you like it. I guess I'll have big one myself.