A 35-year-old man is admitted to the hospital of the suspected viral infection. What is the best method of determining whether or not it is a viral infection?

A. Perform a test on the patient's blood to look for viral antibodies.

B. Look for potential ways the patient may have contracted the infection.

C. Treat with antibiotics to see if patient may have contracted the infection.

Or D. Treat with an antiviral drug and see if the patient improves.

PLEASE HELP!! I am between all the answers! Thanks!