A moment, please．I'm checking if Mr. Smith _________ free tomorrow．

A moment, please．I'm checking if Mr. Smith _________ free tomorrow．

A．is                 B．being                   C．to be                      D．will be

A moment, please．I’m checking if Mr. Smith _________ free tomorrow．

A moment, please．I'm checking if Mr. Smith _________ free tomorrow．

1. A.
   is
2. B.
   being
3. C.
   to be
4. D.
   will be