Answer:
Rotavirus
Step-by-step explanation:
I assume your answer choices are:
Giardia organisms
Shigella organisms
Rotavirus
Salmonella organisms
A viral pathogen is a pathogen caused by a virus.
Therefore It is not Giardia or Salmonella because both are bacterial pathogens, not viral.
And it is not Shigella because Shigella is uncommon.