Answer:
The red balls here refers to the hydrogen and black balls refers to carbon.
I think the correct answer from the choices listed above is option A. Directional selection can be distinguished from disruptive selection by the elimination of extreme variations of traits. Directional selection is a natural selection where an extreme phenotype is favored than others.
The correct answer is the suprachiasmatic nucleus of the hypothalamus. The suprachiasmatic nucleus, as the name suggests, is the part of the hypothalamus located in right above above the optic chiasm. The main function of the suprachiasmatic nucleus is mainly responsible for the circadian rhythm of the body therefore the physiological activity on daily cycles.