a) Virus mostly has RNA as genetic material. But some of the virus like herpes virus has DNA as genetic material.
b) Viruses multiply inside the host cell. They inject the genetic material into the host cell and replicate themselves with the help of host machinery.
c) The virus exists as non- living outside the cell and they are living inside the cell. The viruses which infect the bacteria are known as bacteriophages.
d) Viruses like herpes also contain DNA but mostly virus contains RNA as their genetic material.
So, the correct answer is option B.