Some organisms are capable of asexual or sexual reproduction. Under favorable conditions, reproduction proceeds asexually. When conditions become more stressful, reproduction switches to a sexual mode. Why?

A) Asexual reproduction requires more energy.
B) Sexual reproduction produces individuals with new combinations of recombined chromosomes increasing diversity.
C) Sexual reproduction is simple and more rapid, allowing larger numbers of offspring to be produced.
D) Sexual reproduction requires two separate individuals who can mutually provide nutrient support during stress.