Effectively Combating the Spread of Malaria Has Become More Challenging

Multiple Choice

Effectively combating the spread of malaria has become more challenging since the 1970s because:

A) The Anopheles mosquito has become genetically resistant to most pesticides.
B) Plasmodium parasites have become resistant to most antimalarial drugs.
C) The flea that transmits the disease has become resistant to pesticides.
D) None of these answers.
E) Two of these answers.