If you expose a photosynthesizing plant to water that contains both radioactive h and radioactive o, in which of the products of photosynthesis will the radioactive h and o show up?
a) h and o both in glucose
b) h in glucose; o in glucose
c) h in water; o in glucose
d) h in glucose and water; o in o2
e) h in glucose and water; o in water and o2

D) H in glucose and water; O in O2

Explanation:

In green photosynthesizing plants, photolysis occurs during the light-dependent phase. Photolysis is the splitting of the water molecule in the presence of sunlight. The oxygen atom of water molecules forms oxygen gas that is released as a by-product of photosynthesis. Photolysis also releases electrons and protons from water molecules that finally reduce the NADP into NADPH.

The light-independent phase of photosynthesis fixes reduces CO2 into glucose. NADPH serves as reducing power during the light-independent chemical reactions and therefore, the H atoms from water molecules are incorporated into glucose and water molecules formed during light-independent reactions of photosynthesis.

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).