The LPN is assisting the RN to provide care for a client diagnosed with a traumatic brain injury. Using the Glasgow Coma Scale, when the client does not obey verbal commands to move, which technique will the RN use to evaluate motor function?

a. Squeeze the trapezius muscle firmly
b. Lift the client's arm and observe for pronation and drift
c. Apply fingertip pressure for 10 seconds
d. Rub the sternum with the knuckles