Need explanation for this question (Bio)

skatj
Fri, 09 May 2008 02:49:01 +0000

The LEAST effective means of controlling pest species such as rats or roaches over a long period of time is generally to
A) limit food supplies
B) reduce the number of potential habitats
C) distribute pesticides throughout the habitat
D) introduce predators of the pest
E) introduce a disease which affects only the pest


My initial reaction was natural selection for pests that displayed resistance/immunity against a disease or pesticide, since the question emphasized “over a long period”. From that, I narrowed it down to C or E, but couldn’t end up deciding between the two, and randomly chose E. The answer was C. Is some biological basis that would make C less effective than E?