From which structures do oxygen molecules move from the lungs to the blood?

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

the answer is c. it will give up it's valence electron to the other atom.

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).