This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
The level of which hormone is unchanged in pregnancy 
Select and explain. 
A. Prolactin, B. Growth hormone, C. ACTH, D. Plasma vasopressin
D: Plasma vasopressin
Answer: D: Plasma vasopressin 
Explanation: The levels of ACTH, CRR, and Prolactin increase; the level of GH increases during pregnancy due to its variant syncytiotrophoblast. Plasma vasopressin levels remain unchanged