The window was broken. Try to ________ who has broken it.[ ]

A. find          

B. look            

C. find out      

D. look for

The best characterization of a firm that is operating on its long-run average cost curve is when it:()

A. experiences constant returns to scale.

B. produces a given output at the least possible cost.

C. chooses a plant size that minimizes the average fixed cost.