Answer the following question given this paragraph: 

Figure 7.22 Osteoporosis Osteoporosis is an age-related disorder that causes the gradual loss of bone density and strength. When the thoracic vertebrae are affected, there can be a gradual collapse of the vertebrae. This results in kyphosis, an excessive curvature of the thoracic region.


Q: What is the age-related disorder that causes the gradual loss of bone density and strength?

 Choices:

- mitosis

- arthritis

- fibrosis

- osteoporosis

A:
osteoporosis
