n your backyard you overturn a large rock. In the damp soil underneath the rock, you see various insects scurrying for cover: one black spider, five black ants, two brown beetles, and three gray pill bugs. In this community of organisms, species richness is represented by

a. to encourage apoptosis

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).