Answer:
Stabilizing selection is occurring because the average is favored.
Step-by-step explanation:
There are different types of natural selection: sexual selection, stabilizing selection, directional selection, frequency-dependent selection, and disruptive selection.
Balancing selection, also called Stabilizing selection, eliminates individual with extreme traits and favors individual that exhibit medium-range characteristics, that gets to survive.
In the exposed example, babies with very low or very high birth weight have fewer possibilities to survive. Stabilizing selection eliminates individuals with extreme weight and favors individuals that exhibit medium weight, which are the ones that get to survive.