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.

• A
  $4$
• B
  $2$
• C
  $3$
• D
  $5$