A Client Asks Why a Cast Can't Get Wet

A client asks why a cast can't get wet. Which of the following responses would be the most appropriate?

A) A wet cast can cause foul odor.
B) A wet cast will weaken or be destroyed.
C) A wet cast is heavy and difficult to maneuver.
D) It's all right to get the cast wet, just use a hair dryer to dry it off.