In an area of erratic rainfall, a biologist found that grass plants with alleles for curled leaves reproduced better in dry years, and plants with alleles for flat leaves reproduced better in wet years. This situation would tend to _________ . (Explain your answer.) a. cause genetic drift in the grass population. b. preserve genetic variation in the grass population. c. lead to stabilizing selection in the grass population. d. lead to uniformity in the grass population.