The knee joint is a compound of two synovial joint types; what are they？

The knee joint is a compound of two synovial joint types; what are they？
A.a condyloid and a plane joint
B.a condyloid and a saddle joint
C.a saddle and a hinge joint
D.a condyloid and a pivot joint
E.a plane joint and a pivot joint
正确答案：a condyloid and a saddle joint