An OTA Is Measuring Shoulder Extension on a Client

An OTA is measuring shoulder extension on a client. Once the client is positioned, how should the OTA instruct the client?

A) "Keep your elbow straight and reach your arm up toward the ceiling."
B) "With your elbow straight, move your arm straight back behind you as far as possible."
C) "Move your arm away from the side of your body, with the palm facing forward."
D) "With your elbow straight, bring your arm across the front of your body."