The Patient,age 52,is Recovering from a Modified Radical Mastectomy

The patient,age 52,is recovering from a modified radical mastectomy.Why is postoperative elevation of the patient's arm important after this procedure?

A) To prevent vascular and lymph stasis,thus lymphedema.
B) To prevent drainage accumulation at the incisional site.
C) To prevent wound infection and dehiscence.
D) To prevent pleural effusion and respiratory distress.