Many Scientists Think the Great Number of Parasite Species on Earth

Multiple Choice

Many scientists think the great number of parasite species on Earth can be explained by the specialization parasites have undergone and continue to undergo.Which factor is likely most responsible for the continued evolution of new forms of parasites?

A) Highly resistant host immune systems
B) Stable, unchanging host environments
C) Constantly changing host environments
D) The ability of most parasites to kill their hosts and move to new ones
E) The ability of parasites to become more deadly with each generation