Is this the reason _____ she explained in the report for her success in the job?

A．what               B．that           C．how          D．why

This is the reason ______ she explained in the report for her success in the job.

This is the reason ______ she explained in the report for her success in the job.

A．what             B．that              C．how              D．where

This is the reason ______ she explained in the report for her success in the job.

1. A.
   what
2. B.
   that
3. C.
   how
4. D.
   where