The introductory passage discusses the way that virophages interfere with the ability of megaviruses to reproduce and the possible selective benefits of this. However, there are many ways that cells attempt to survive attacks by viruses. According to the chapter, what is another way that cells have evolved to avoid viral infection?

a. An attachment receptor on the host cell surface that is recognized by the virus is mutated.
b. A mutation in the host blocks translation at the ribosome.
c. Cells undergo a phenomenon called circular permutation, in which the same set of genes is arranged differently in each individual.
d. The host develops enzymes that cleave the restriction endonucleases of the virus.