Source of infection in diseases like Tuberculosis, Mumps and Whooping cough is A. Direct contact B. Droplets of saliva C. Carrier organism D. A vector

Direct contact is not the primary source of infection for these diseases. However, it is possible to become infected with tuberculosis if you come into contact with an open wound that is infected with the bacteria.

A carrier organism is a living thing that carries a disease-causing organism without showing any signs of illness. Carriers can spread the disease to others, even though they are not sick themselves.

A vector is an animal that carries a disease-causing organism from one host to another. Vectors can be insects, such as mosquitoes, or ticks.

In conclusion, the correct answer is: B. Droplets of saliva.