A rounded projection that enters into the formation of a joint is a:

A) fossa.
B) trochanter.
C) sinus.
D) condyle.

Condyle

A rounded projection on a bone, typically at the joint, where it connects with another bone.

Trochanter

A large, bony prominence found on the femur, serving as a major attachment point for muscles.

Fossa

A depression or hollow, often found in bones or in the body, serving various purposes like accommodating muscles or organs.