One AU is roughly the mean distance from the earth to the moon, more specifically its approximately 93 million miles(150million km). AU is used for measuring the distance of planets and other objects in our solar system. it is used because it provides a convinet way to express and relate distances and objects.
The answer should be C because the DNA in the genes is what causes genetic mutations. The sequence differs from what is found in most people. Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes.
Technique b is more advantageous because if they used technique a. The bees that pollinate the crops would die and the crop would not make more seeds. Hope this helps(: