Which is a part of the cell theory? a)cells come from pre-existing cells b)cells have a nucleus c)organisms with one cell must be seen with a microscope d)organisms must have more than one cell to live

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).