A. Fungus
B. Virus
C. Protist
D. Bacteria
The doctor refuses to prescribe antibiotics to the patient because the illness is caused by a virus. The common cold is a viral infection of the upper respiratory tract. Antibiotics are not effective against viral infections and are only used to treat bacterial infections.
The other options are not correct because they do not accurately describe the cause of the common cold and sore throat. Fungus, protist, and bacteria are not the pathogens responsible for causing the common cold.
Therefore, the Correct Answer is B.