The correct answer is: Flexion of the wrist

Palmaris longus is a small muscle in the anterior compartment of the arm--it flexes the hand at the wrist and tightens the palmar aponeurosis. If this tendon was cut, it would be more difficult to flex the wrist. Flexor pollicis longus flexes the MP and IP joints of the thumb. Flexor digitorum profundus and superficialis flex the proximal IP joints of digits 2, 3, 4, and 5. Extensor carpi ulnaris, extensor carpi radialis longus and extensor carpi radialis brevis all extend the wrist.