Answer:
A) the output
Explanation:
The production function describes a boundary or frontier representing the limit of output obtainable from each feasible combination of inputs.
Firms use the production function to determine how much output they should produce given the price of a good, and what combination of inputs they should use to produce given the price of capital and labor.
The production function also gives information about increasing or decreasing returns to scale and the marginal products of labor and capital.