14. The most likely method by which the mu-
tated CCR5
gene prevents AIDS is by
(A) blocking the protein channels that allow
the virus to enter the cell.
(B) directing the formation of lytic enzymes
packaged
in the lysosomes.
(C) being presented on immune system cells to
target
the virus for attack and destruction.
(D) coding for a mutant receptor protein on
the cell membrane
, thus not allowing the
entry
of the
virus
.