―Hello , Ben .  I’m just checking if you can pick up Mary at the airport this evening.  

― Oh , yes , I __________ you about that .  But I have to go to my daughter’s school play .  

A. will phone                                                   B. have phoned

C. am phoning                                                 D. was going to phone

--- Hello, Ben. I’m just checking if you can pick up Mary at the airport this evening.

--- Oh, yes, I          you about that. But I have to go to my daughter’s school play.

A．will phone                                    B．have phoned

C．am phoning                         D．was going to phone