The best answer is C.
Gene cloning can involve inserting genes into a plant.
Gene cloning is the deliberate addition of a foreign gene to the genome of an organism. A gen holds the information that will give the organism a trait.
Genetic engineering removes the DNA from one organism and transfers the gene or genes for one or more traits into another. Since in this process crossing is not necessary, the "sexual" barrier between species is overcome. Therefore traits from any living organism can be transferred into a plant.