About Twice a Year, Charles's Sales Manager Goes with Him

About twice a year, Charles's sales manager goes with him to visit clients. What is the most likely reason for the sales manager's actions?

A) It is a good supervisory method.
B) The sales manager wants to keep her own sales license current.
C) If the sales manager does not use the money allotted to her expense account, she will lose it.
D) The sales manager likes to spy on her sales reps.
E) The sales manager is trying to get a share of Charles's commission for herself.