This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
Example of physiological atrophy is- 
Select and explain. 
A. Decrease in uterus size after delivery, B. Disuse atrophy, C. Atrophy of a muscle after nerve damage, D. Senile atrophy
A: Decrease in uterus size after delivery
Answer: A: Decrease in uterus size after delivery 
Explanation: Ans. is 'a' i.e., Decrease in uterus size after delivery Atrophy* Atrophy is the reduced size of an organ or tissue resulting from a decrease in cell size and number. Atrophy may be physiological (atrophy of notochord and thyroglossal duct during fetal development; decrease in uterus size after delivery); or pathological (e.g. disuse atrophy, denervation atrophy, senile atrophy etc).