Stabilizing selection is the correct answer.

Explanation:
Stabilizing selection, also known as balancing selection, is a type of natural selection that favors the average or intermediate phenotype in a population. It occurs when extreme phenotypes are selected against, leading to a reduction in phenotypic variation over time.

When it comes to mortality in babies, stabilizing selection is a relevant concept. Here's an explanation of why mortality in babies can be considered an example of stabilizing selection:

1. Mortality in Babies:
- Mortality in babies refers to the death rate among infants, usually measured within the first year of life. It is influenced by various factors, including genetic, environmental, and socio-economic factors.
- Mortality in babies is a significant concern globally, and efforts are made to reduce infant mortality rates through various interventions and healthcare initiatives.

2. Stabilizing Selection:
- Stabilizing selection favors the average or intermediate phenotype, reducing phenotypic variation in a population.
- In the context of mortality in babies, stabilizing selection can be observed in the selection against extreme phenotypes that are more susceptible to death during infancy.
- Babies with extreme phenotypes, such as those with severe genetic disorders or developmental abnormalities, may have a higher risk of mortality compared to babies with average or intermediate phenotypes.
- As a result, stabilizing selection acts to reduce the phenotypic variation in the population by favoring babies with average or intermediate phenotypes, which have a higher chance of survival.

3. Example:
- For example, consider a population of babies with varying birth weights. Babies with extremely low birth weights may have a higher risk of mortality due to underdevelopment and associated health complications.
- In this case, stabilizing selection would favor babies with average or intermediate birth weights, as they have a higher likelihood of survival compared to those with extremely low or high birth weights.
- Over time, the population's birth weight distribution would tend to stabilize around the average or intermediate values, thus reducing the variation in birth weights.

In conclusion, mortality in babies can be considered an example of stabilizing selection, as it favors babies with average or intermediate phenotypes and reduces phenotypic variation in the population.