The correct answer is option Stabilizing selection is occurring because the average is favored.
In stabilizing type of natural selection, the individuals having the average phenotype are promoted. The extreme phenotypes are ultimately eliminated.
The birth weight of the humans should be maintained to an average value. In case, the weight of the child at the time of the birth is extremely less it would be hard for the baby to survive. In order to survive better, proper amount of nutrition in body is required. In case, the weight of the baby is so less, then the amount of the stored nutrients in the body would be so less, hence, it would not survive.
In other case, if the weight of the baby is too much, then the delivery of the baby would be very complicated. The passage of the baby through the birth canal would not be possible. Other than this, the baby would be born with obese condition, which can hamper the health of the child. Hence, the maintenance of an average weight is required.