Answer:
The correct option is: c. a doorknob contaminated with the cold virus
Step-by-step explanation:
Fomites are the inanimate objects or substances that can get contaminated with the pathogens and are capable of transferring the pathogens to the new hosts.
Sterilization of the possible fomites should be done in order to prevent cross-infection.
Examples of fomites are hair, towels, clothes, door knobs, cups, switches, handrails, remote controls, pens, syringes, bedding, etc.