Explanation
The head of the humerus bone is articulated with the pectoral girdle by a ball and socket joint.
A ball and socket joint is a synovial joint in which the rounded surface of one bone (the ball) fits into the concave surface of another bone (the socket). The humerus bone has a rounded head that fits into the shallow socket of the scapula bone in the pectoral girdle. This joint allows for a wide range of movements, including flexion, extension, abduction, adduction, and rotation.
A hinge joint allows for movement in only one plane, like the elbow joint, which allows for flexion and extension. An immovable joint, also known as a synarthrosis, does not allow for any movement and is found in the skull. A pivot joint allows for rotation around a central axis, like the joint between the atlas and axis bones in the neck.
Therefore, the correct answer is B: Ball and Socket joint.
