Under which of the following conditions are you most likely to fall sick?
(a) when you are taking examinations
(b) when you have travelled by bus and train for two days
(c) when your friend is suffering from measles. Why?

Option- (c) when your friend is suffering from measles.

You are most likely to fall sick when your friend is suffering from measles because measles is caused by a virus that's why it is a highly contagious disease which can be easily spread through respiration.