If a Muscle Crosses the Metacarpophalangeal and Interphalangeal Joints of Fingers

If a muscle crosses the metacarpophalangeal and interphalangeal joints of fingers two through five on the dorsal (posterior) side with a vertical orientation to its fibers,what will its action most likely be?

A) flexion of the fingers at these joints
B) extension of the fingers at these joints
C) abduction of the fingers at these joints
D) adduction of the fingers at these joints