had/have had three cups of tea this morning

[Vik-Nik-Sor]

________ three cups of tea this morning but I think I'm going to have a coffee after my lunch.
A I had
B I was having
C I've had
D I've been having

The key answer is C. I understand it implies that it's still morning. But the sentence says that I'm no longer going to have a coffee before lunch. So, may not I use "A"?
Thanks.

 

[Rover_KE]

I would accept A or C.

 

[MikeNewYork]

A or C would also be acceptable in AmE.

 

[Tdol]

The present perfect works better for me, but, like Rover, the past works too.