The graph below illustrates a series of short-run average cost curves, numbered AC through AC 1 4 , which correspond to the only four different automobile plant sizes possible. a. What can you say about returns to scale? (Click to select) constant returns increasing returns decreasing returns b. Are economies of scale present? (Click to select) Yes No c. If, in this automobile plant, it takes 42 workers and 104 units of capital to produce 120 automobiles a day, how much labour and capital is involved in producing 360 automobiles a day? workers and units of capital unalily ul aulus el uay.