According to Porter's five forces model, a student's choice of lunch options at a large food court would be an example of a strong force for .

Threat of substitutions.

Explanation:

Th threat of substitution is defined as the availability of a product that the consumer can purchase instead of the industry's product. The student chooses to buy from the food court despite being in a position to buy from other places with the similar product.The threat of a substitute is the level of risk that a food court faces from replacement by its substitutes.

positive reinforcement? ?