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: Social & Preventive Medicine
MMR vaccine is recommended at the age of: 
Select and explain. 
A. 9-12 months, B. 2-3 years, C. 10-19 years, D. 15-18 months
D: 15-18 months
Answer: D: 15-18 months 
Explanation: None