Question

question 1 of 10
which makes viral infections difficult to defeat?
a. macrophages work slowly.
b. viruses live outside of cells.
c. viruses are attacked by a nonspecific immune response.
d. the immune system must attack the bodys own cells.

Explanation:

Viruses invade host cells. To eliminate them, the immune system has to target infected body cells. Macrophages can act quickly (so A is wrong). Viruses mainly live inside cells (so B is wrong). There are specific immune responses against viruses (so C is wrong).

Answer:

D. The immune system must attack the body’s own cells.