Which of the following is true of rna compared to dna?
a. it lacks phosphate groups.
b. it is a single-stranded molecule.
c. its nucleotides do not have sugars.
d. it contains four different nucleotides.

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).