Many mosquito populations today are resistant to pesticides that were historically effective. this pesticide resistance arose in these populations because: a) the pesticides caused mutations in the dna of mosquitoes that conferred resistance phenotypes, and these mutations were passed on to subsequent generations. b) populations had to develop tolerance in order to survive. c) individual mosquitoes build up immunity to the pesticides after exposure. d) some individuals were resistant to the pesticides before they were used, and those mosquitoes were more likely to survive and reproduce. e) these populations were outside the range of the original pesticide application.