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
All are platelet aggregators except: 
Select and explain. 
A. ADP, B. Thromboxane, C. Steroids, D. PGD2
D: PGD2
Answer: D: PGD2 
Explanation: Ans- D PGD2 Ref: Robbins Pathologic Basis of Disease, 8th edition, Pg: 589 Explanation: Platelet aggregation stimulators ADP. Thromboxane, and a 2 receptor-activation, but Exogenous anabolic steroids Platelet aggregation inhibitors PGI2 PGD2.