Select each correct answer. More than one answer may be correct.
Meiosis, which occurs during sexual reproduction, allows for a great variety of possible gene combinations. Which of the following can increase genetic variation during meiosis?

A.) the exchange of genes during chromosomal crossover
B.)the transposition of a gene from one place in an organism's genome to another
C.)the duplication of a gene caused by an error in chromosomal crossover
D.) the deletion of a gene caused by an error in chromosomal crossover