Answer
d. all of the above
Work Step by Step
Causes of the given ailments are:
1. Otitis media: It is caused by infection in the Eustachian tube by multiple bacteria.
2. Hospital-acquired Pneumonia: It is caused by inhaling air infected with different kinds of bacteria in a hospital or touching infected surfaces /patients.
3. Sinusitis: Caused by a biofilm made by various types of bacteria.
Thus, the correct answer is option d.