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: Gynaecology & Obstetrics
Following hormones secreted by placenta exclusively :a) HCGb) Estrogenc) HPLd) PRL 
Select and explain. 
A. a, B. bc, C. ac, D. b
C: ac
Answer: C: ac 
Explanation: Placenta produces a number of hormones.