Conductive Gel Is Applied to the Client's Skin Before Using

Conductive gel is applied to the client's skin before using Doppler ultrasound to facilitate the movement of the ultrasound beam.To assist with this process,the nurse must ensure that

A) The old gel is removed before applying new gel.
B) An airtight seal is maintained between the probe and skin.
C) The Doppler machine is turned to the OFF position until it is placed on the skin.
D) The gel is liberally spread over a 2 cm × 2 cm area on the client's skin.