B

Symphyses are secondary cartilaginous joints (amphiarthroses) with fibrocartilage uniting the bones and only slight mobility, not true diarthroses/synovial joints. Plane (gliding), condyloid, and saddle joints are all synovial (diarthrodial) joints that permit free movement [Mow 1992, PMID 1550898; Bettermann 1991, PMID 1681698].