Answer:
C) all the input combinations that can be purchased at a given total cost.
Explanation:
The isocost formula is C =wL + rK
where:
The isocost line shows the different combinations of inputs that can be purchased for a given level of total expenditure (C) at given input prices (w, r).
The total costs should be minimized at the point where the isocost line intersects with the isoquant line (shows all possible input combinations capable of producing a given level of output).