A population of mosquitoes is exposed to the pesticide DDT for several generations. At the end of that time, most individuals in the population are resistant to DDT. The most likely reason is that: A. random mutations in each generation made mosquitoes resistant to DDT.
B. some individuals in the original population had the mutations that led to resistance.
C. DDT caused the mutations that led to resistance.
D. somatic mutations in the original population were passed on to subsequent generations.
E. by chance, new mutations that led to DDT resistance arose after DDT was used.