The is a prime mover of the glenohumeral joint during flexion.

It would be the DELTOID. The deltoid is the main mover of the glenohumeral joint during flexion. The deltoid is the muscle that forms our shoulders. It is located in the uppermost portion of our arm. During flexion, what we do is that we bend our arms and when we bend our arms, the primary muscle that makes this possible to move is the deltoid.

The answer would be d because x,y = male and x,x = female so x,y is male so xxy is male with a female trait!