In western countries, when your friend offers (提供 )you something,  you can accept it directly(直接地), or refuse it politely.  Therefore, which situation fits the western custom?

A：At a restaurantA: Help yourself to some fish.B:  No. I don't like eating fish at all.

B：At your birthday party   A: Here's a present for you.B: I don't need it. You shouldn't spend so much money.

C：At a barA: Would you like something to drink, beer or wine?B: A glass of beer, please.