table below. In this instance, expansion of output Q P TR MR TC MC 0 $30 0 --- $15 --- 1 $30 $30 $30 $25 $10 2 $30 $60 $30 $40 $15 3 $30 $90 $30 $60 $20 4 $30 $120 $30 $85 $25 5 $30 $150 $30 $115 $30 6 $30 $180 $30 $150 $35 Question 4 options: a) occurs because of increasing returns to scale. b) causes diseconomies of scale to occur. c) leaves input prices constant as demand for inputs increases. d) causes input prices to rise as demand for inputs decreases