Law homework help

Supply: Q S = 20 P – 100 Where Q is Quantity measured in tons, and P is the Price in $ per ton. The Government decides to provide producers with a subsidy of $4 per ton. The competitive model predicts that, as a result of the subsidy, the equilibrium marke t price will fall by: A. $0.80 per ton B. $1.20 per ton C. $1.60 per ton D. $8.00 per ton  Explain your answer.