Final answer:
Senility is the least likely to cause atrophy in muscles.
Step-by-step explanation:
Sarcopenia, which refers to muscle atrophy with age, is irreversible and often affects older individuals who are sedentary. The loss of muscle cells can lead to functional impairments such as trouble with locomotion, balance, and posture. These effects can be seen as a decrease in quality of life, medical problems, and an increased risk of injuries due to falls. Therefore, senility is the LEAST likely to cause atrophy.