Why did smaller animals replace larger Ice Age creatures?

The option that smaller animals thrived in warmer weather is correct because, as the Ice Age came to an end, the global climate began to warm, leading to changes in ecosystems and habitats. As temperatures increased, environments shifted from cold tundras to warmer and more temperate zones, which favored smaller species that could adapt more readily to these new conditions. These animals often required fewer resources and could reproduce more quickly, allowing them to maintain stable populations in changing environments. Larger animals, on the other hand, often needed more food and had slower reproductive rates, making them more vulnerable to extinction as their habitats changed and resources became scarce. This dynamic allowed smaller animals to flourish in the post-Ice Age period, establishing new ecological balances.