This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
The intense craving experienced by the people recovering from chronic alcoholism can be treated by a drug which acts by being an: 
Select and explain. 
A. Agonist of serotonin receptors, B. Agonist of alpha adrenoceptors, C. Agonist of beta adrenoceptors, D. Antagonist of opioid receptors
D: Antagonist of opioid receptors
Answer: D: Antagonist of opioid receptors 
Explanation: (Ref: KDT 6/e p467) Naltrexone is used to decrease the craving for alcohol after de-addiction.