Answer:
The correct option is : b. long-term use of broad-spectrum antimicrobials
Explanation:
A superinfection is a secondary infection. It is caused when a cell which has been previously infected by a microbe, gets infected again by another microbe of endogenous or exogenous origin. This happens when the second microbe is resistant to the treatment being used for the treatment of the infection caused by the first microbe.
Treatments involving the long-term use of broad-spectrum antimicrobials can increase the rick of a superinfection.