Identify the odd one out.

Read the following statements carefully and determine how many statements are correct?
$(1)$ Typhoid typically has an incubation period of $1-3$ weeks.
$(2)$ The fungus $Pneumocystis$ is responsible for causing pneumonia in $AIDS$ patients.
$(3)$ Sudden withdrawal of addictive substances leads to withdrawal syndrome.
$(4)$ In cancer,all treatments can be given simultaneously.
$(5)$ Athletes use steroids to enhance their performance.

The enlargement of the spleen during malaria is caused by:

In which way has the study of biology helped us to control infectious diseases?

How does the transmission of each of the following diseases take place?
$(a)$ Amoebiasis
$(b)$ Malaria
$(c)$ Ascariasis
$(d)$ Pneumonia

Which of the following pairs is mismatched?