Final answer:
Degenerative changes in the skeletal system typically begin around the age of 30-45. Bone mass peaks at 30 and then decreases, with conditions like Paget's Disease common in adults over 40. Menopause in women around age 50 can lead to accelerated bone mass loss due to reduced estrogen.
Step-by-step explanation:
The skeletal system begins to exhibit degenerative changes typically around the age of 30-45 years. Bone density reaches its peak at about 30 years of age and thereafter, individuals may start to lose bone mass. This process can be accelerated in women, especially around the age of 50, which is when menopause often occurs, leading to a reduction in estrogen levels that stimulates osteoblastic activity and bone matrix production. Therefore, the onset of skeletal degeneration aligns most closely with option c) 30-45, as bone density peaks at 30 and then begins to decrease, potentially contributing to conditions like osteoporosis. Paget's Disease is another example of a skeletal system condition that typically occurs in adults over the age of 40, highlighting the increased susceptibility to degenerative bone diseases as one age.