The correct answer to this question is A, Extensor. The full name of the muscle is extensor digitorum. It is a very long muscle. The extensor muscle connects to the outside of the elbow, down the forearm, and then connects to the middle of four fingers. It has controls in the hands and wrist.
One control is that it straightens the 3rd, 4th, and 5th fingers. It also helps straighten out the wrist. This muscle can have pain from things we do every day, like typing, playing tennis, repeatedly grabbing an object like a pen or pencil, using a screwdriver, and knitting.