Viruses are a type of biological agent that needs a host to replicate and spread. an example of this biological agent is:

An example of a biological agent that needs a host to replicate and spread is a smallpox. Smallpox is an airborne disease, can be transmitted from person to person through air by close contact, that is contagious caused by a variola virus. Before, it was one of the deadliest diseases known to mankind. The last devastating case was in Somalia in 1977 and was declared to be eliminated by World Health Organization in the year 1980.

North carolina ranks second in christmas tree production has nothing to do with biotechnology

Well i had the same answer, so the correct answer would be a. but in this case it would be the one with plasma membrane and cell wall circled that is next to the hairy pill type of thing.