Answer:
Its been used by humans to take the best traits from a species and pass them on like bigger bodies in cows for more meat and bigger muscles in horses for faster racing potential.
The disk diffusion test is used to compare the effectiveness of antibiotics. The incubated plate (results) will show bacteria growth except where antibiotic has effects. The more effective the drug, the inhibition zone will be greater. So the most effective antibiotic is the one that has the largest inhibition zone around the test site.
C.only determines phenotype when a dominant allele for the same trait is present.