Which of the following statements is true?

The correct statement is:

B) The skull has many immovable joints, connecting various bones.

The skull is made up of several bones that are connected by sutures, which are immovable joints.

To clarify the other options:
A) The wrist is not a ball-and-socket joint; it is primarily a complex joint involving ellipsoidal (condyloid) movements.
C) The elbow is a hinge joint, not a saddle joint.
D) The skull does have joints (sutures), so it is not accurate to say it has no joints.