The knee joint consists of three primary compartments:

1. Medial compartment: The inside part of the knee, which includes the femur and tibia interaction on the inner side.

2. Lateral compartment: The outside part of the knee, where the femur and tibia meet on the outer side.

3. Patellofemoral compartment: The area between the patella (kneecap) and the femur.

These three compartments are essential for knee joint stability and function, allowing movement and weight-bearing activities.

B. Trochlea groove and vestibular are not associated with knee anatomy.

C. Posterior malleolus, scapula, and fibular facet do not relate to knee compartments; the malleolus is in the ankle, scapula in the shoulder, and fibular facet is not part of the primary knee compartments.

D. Cochlea is unrelated to knee anatomy and refers to a part of the inner ear.

Thus, the correct answer is A. Medial, lateral, and patellofemoral.