Final answer:
The maximum output for a given amount of input is defined by a production function (B). It is an economic concept that describes the relationship between inputs and the resulting output, affected by fixed and variable inputs.
Step-by-step explanation:
The correct answer to the student's question is B. production function. A production function is a concept in economics that describes the relationship between the quantity of inputs used in the production process and the quantity of output that is produced. This function allows us to understand how much output a firm can produce given different amounts of inputs, which can vary based on the specific product and the firm's methods of production. Inputs in production can be categorized as either fixed or variable. Fixed inputs are those that cannot be easily changed in the short term and define the firm's maximum output capacity. For example, in a pizza restaurant, the building would be a fixed input, setting the limit for how much pizza can be produced at that location.