All of the following factors contribute to hospital-acquired infections except

All of the following factors contribute to hospital-acquired infections EXCEPT

Select one:

a. some bacteria metabolize disinfectants.

b. bacteria may be present in commercial products such as mouthwash.  

c. invasive procedures can provide a portal of entry for bacteria.  

d. gram-negative bacteria are often resistant to disinfectants.  

e. None of the answers is correct; all of these factors may contribute to hospital-acquired infection.

e. None of the answers is correct; all of these factors may contribute to hospital-acquired infection.

is there any answer choices to this?