Question

which bone is the keystone of the lateral longitudinal arch of the foot?
a) navicular
b) talus
c) cuboid
d) calcaneus

Explanation:

The lateral longitudinal arch of the foot is supported by the calcaneus (heel bone), cuboid bone, and the fourth and fifth metatarsals. The cuboid bone acts as the keystone in this arch. The navicular is part of the medial longitudinal arch, the talus is a key bone in the ankle - foot complex but not the keystone of the lateral longitudinal arch, and the calcaneus is a foundational bone of the foot but not the keystone of the lateral longitudinal arch.

Answer:

C. Cuboid