Once overweight, Brenna's mother has started to lose weight as she's aged. At first, Brenna was happy to see this because she thought it may help her mother bounce back from future injuries. On the contrary, Brenna has started to notice that her mother is having more difficulty with walking and climbing stairs. Her doctor explains that this declining function is common in adults age 65 and older. What term describes the muscle wasting Brenna's mother is experiencing? a. sarcopenia
b. aphasia
c. kyphosis
d. xrostomia