A bone is covered externally with a sheath called ______, whereas the internal surface is lined with ______.

Choice A reason: Arms do not perform inversion or eversion. Their movements include flexion, extension, abduction, and rotation, but not these specific terms.

Choice B reason: Hands perform movements such as flexion, extension, abduction, adduction, and opposition, but inversion and eversion are not applicable.

Choice C reason: Feet only is the correct answer. Inversion refers to turning the sole of the foot inward, while eversion refers to turning it outward. These movements occur at the subtalar joint and are essential for balance and gait.

Choice D reason: Hands and feet is incorrect because inversion and eversion are exclusive to the feet. Hands do not perform these motions.

Choice E reason: The neck performs flexion, extension, rotation, and lateral bending, but inversion and eversion are not associated with cervical movement.

Choice A reason: Appositional growth is the correct answer. It refers to the process by which bones increase in diameter or thickness. This occurs when osteoblasts in the periosteum lay down new bone matrix on the outer surface, while osteoclasts resorb bone on the inner surface to maintain proper proportions.

Choice B reason: Concentric growth is not a recognized term in bone physiology. It may refer to circular layering in osteons but not to bone thickening.

Choice C reason: Interstitial growth occurs within cartilage and is responsible for lengthening during development. It does not contribute to bone thickness.

Choice D reason: Circumferential growth is a vague term and not commonly used in bone biology. It may imply growth around the circumference but is not the standard term for bone thickening.

Choice E reason: Epiphyseal plate closure marks the end of longitudinal bone growth during adolescence. It does not relate to increasing bone thickness.