Answer: knee.
- A knee
- B shoulder
- C hip
- D base of the skull
Correct answer: A. knee
Explanation: The knee (and elbow) is a hinge joint, moving like a door hinge.

A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.