Research has identified a species from the west coast of the United States which may have been the ancestor of 28 distinct species on the Hawaiian Islands. What is this species?

b.have there own function.

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).