The diploid is 30. The haploid is 15. Option C is most likely correct.
The answer is B. artificial selection. Artificial selection is . a process in the breeding of animals and in the cultivation of plants by which the breeder chooses to perpetuate only forms that have certain desirable inheritable characteristics (such as, in this case, cows that produce the most milk).
The answer is the second statement.
Quanitative refers to numbers. The only statement that contains a numerical information is "the tree was 20 years old when it was cut down".
The other statements only contain qualitative information.