Write a letter to the editor of a newspaper advocating that "classroom in 21st century should be internet friendly".

answer: b (host)

viruses use the cells of living organisms to reproduce. the cell which is used by virus is called as "host cell". it is a living cell in which virus multiplies, example bacteria, plant or an animal cell.

in this, the virus is a parasite, which uses host cell for its benefit (reproduction) by using the cell machinary of host cell.

i cannot see any of the options                                                                        

a. they have shared matter.