Scenario 12-12 If Farmer Brown Plants No Seeds on His Farm,he Gets

Scenario 12-12
If Farmer Brown plants no seeds on his farm,he gets no harvest.If he plants 1 bag of seeds,he gets 5 bushels of wheat.If he plants 2 bags,he gets 9 bushels.If he plants 3 bags,he gets 12 bushels.A bag of seeds costs $120,and seeds are his only cost.
-Refer to Scenario 12-12.Farmer Brown's total-cost curve is

A) increasing at an increasing rate.
B) increasing at a decreasing rate.
C) increasing at a constant rate.
D) decreasing.