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: Pharmacology
Sibutramine is ? 
Select and explain. 
A. Antithyroid drug, B. Antiobesity drug, C. Antimalarial drug, D. Antitubercoulous drug
A: Antithyroid drug
Answer: A: Antithyroid drug 
Explanation: Ans. is 'a' i.e., Endorphines Endorphins have major action on receptors. Enkephalins have major action on a receptors. Dynorphins have major action on c receptors.