Use the following market data to answer the question below.
Price per Unit Quantity Purchased by Consumer Quantity Sold by Producer
$5 2,000 0
10 1,800 300
15 1,600 600
20 1,400 900
25 1,200 1,200
30 1,000 1,500
In the market shown in the table the marginal cost of 600th unit is:
a) $10
b) $15
c) $20
d) $25