Rabbits are herbivores that are not native to Australia. Their numbers have steadily increased since they were introduced to Australia by European
settlers. One likely reason the rabbit population was able to grow so large is
that the rabbits *

A were able to prey on native herbivores.

B reproduced more slowly than native animals.

C could interbreed with native animals.

D outcompeted native herbivores for food.

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).