According to the passage, research suggests that one possible reason the Africanized bees in Brazil have successfully resisted Varroa jacobsoni is that A. the life cycle of the Africanized bee may limit the Varroa jacobsoni mite's opportunity to reach full development B. the Africanized bees may have had an opportunity to develop a chemical resistance to Varroa jacobsoni C. the location of bee colonies in Brazil may provide a natural deterrent to Varroa jacobsoni D. Varroa jacobsoni may be relatively new to Brazil and may not have had time to become widespread E. beekeepers may have developed effective control techniques for Varroa jacobsoni