The main theme of "The Two Offers" is

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.

c is the answer because first she would blush to make the reader wonder why which they find out in the next line.

earthquake is the answer i remember doing this last year