Choice C rationale:

Kyphosis is the medical term for the excessive outward curvature of the spine that the nurse observes in this client.

Kyphosis results in a forward rounding of the back and is often seen in older adults with osteoporosis.

When osteoporosis weakens the vertebrae, they become more prone to compression fractures, leading to the characteristic hunched posture of kyphosis.

Choice A rationale:

Scoliosis is not the correct term for the excessive outward curvature of the spine observed in this client.

Scoliosis is characterized by a lateral (side-to-side) curvature of the spine, not a forward rounding of the back.

Choice B rationale:

Lordosis is also not the correct term for the excessive outward curvature of the spine observed in this client.

Lordosis is an excessive inward curvature of the spine, typically in the lumbar (lower back) region, creating a swayback appearance.

Choice D rationale:

Osteoarthritis is unrelated to the observed spinal curvature.

Osteoarthritis is a degenerative joint disease that primarily affects joints, not the overall curvature of the spine.