a virus a protist a fungus a bacterium
I gave my students this multiple choice question: Dr. Wagner is investigating a newly discovered, disease-causing agent. She determines that one structure in the agent is double-stranded RNA. What kind of agent is Dr. Wagner studying?

Only one answer is correct among these 4 choices:
- a virus
- a protist
- a fungus
- a bacterium

Could you tell me which one is correct?

a virus