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
Which of the following is true of chicken pox ? 
Select and explain. 
A. Virus not found in scab, B. Virus can be grown on the chick embryo, C. Caused by RNA virus, D. Does not cross the placental barrier
A: Virus not found in scab
Answer: A: Virus not found in scab 
Explanation: Ans. is 'a' i.e., Virus not found in scab The fluid of vesicle of chickenpox contains virus during first 3 days of illness, but scab is noninfective. About other options Option b VZV does not grow in experimental animal or chick embryo. It can be grown in tissue culture cell lines ---> Human fibroblast, hela cells, vero cells. o Option c VZV is a DNA virus. o Option d VZV can cross placenta and infect the fetus.