Question

which phrase best defines a prototype? the final product, which has undergone extensive testing and redesign a model that has been redesigned and retested several times the criteria established to help solve a problem a model from which later versions are developed

Explanation:

A prototype is an early - stage model from which later, more refined versions are developed. It is not the final product, nor the criteria for solving a problem.

Answer:

a model from which later versions are developed