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
All are true about measles except - 
Select and explain. 
A. Incubation period is 10-14 days, B. Secondary attack rate is 30-40%, C. Sub cutaneous vaccine is available, D. Vaccine is live attenuated
B: Secondary attack rate is 30-40%
Answer: B: Secondary attack rate is 30-40% 
Explanation: SAR of measles is approximately 80%.