Viruses Are Difficult for the Immune System to Deal with for All

Multiple Choice

Viruses are difficult for the immune system to deal with for all of the following reasons, EXCEPT viruses

A) must be located and cleared from infected host cells.
B) have few conserved external structures that the immune system can use to identify them.
C) evolve more slowly than their hosts.
D) are often wrapped in a membrane layer that is nearly identical to the host cell membrane.