Which Is the Most Effective Way for the Nurse to Apply

Which is the most effective way for the nurse to apply an appliance such as a hot water bottle or disposable hot pack to a client?

A) Directly to the client's skin
B) Directly to the client's skin with a towel or blanket wrapped over the appliance to hold it to the leg
C) If possible,have the client lay on top of the appliance
D) Wrap the appliance in a towel and lay it on the site on the client