Biology

The correct answer is: D.gradualism.

Explanation:

If all the transitional forms for a species, like the horse, are found in the fossil record, it suggests that the species evolved through gradual, continuous changes over time. This is consistent with the model of gradualism, where small, incremental changes accumulate slowly over long periods.

The other models do not align with this scenario:

A.Adaptive radiation involves the rapid diversification of a single ancestral specie...