_________ a lot of troublesome affairs to deal with,our boss doesn't have any time to spend holidays.

A.Thanks to                  B.For                   C.With                         D.In case

_________ a lot of troublesome affairs to deal with,our boss doesn't have any time to spend holidays.

1. A.
   Thanks to
2. B.
   For
3. C.
   With
4. D.
   In case