This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
Which of these hormones peaks in the 1st trimester of pregnancy? 
Select and explain. 
A. Estrogen, B. Relaxin, C. Progesterone, D. Prolactin
B: Relaxin
Answer: B: Relaxin 
Explanation: (B) Relaxin