Question: In the 1970s, the pesticide DDT was used to kill insects that damaged fruit and vegetable crops. Most insects died from being exposed to DDT, but some survived. These surviving insects contributed to an increase in their population by

  Options: 
 A. migrating to habitats that had different types of crops.
 B. learning how to avoid being exposed to DDT.
 C. passing the gene for DDT resistance to their offspring.
 D. competing with other types of insects for food.
Answer: C