On an Average Day,a Company Writes Checks Totaling $1,500

On an average day,a company writes checks totaling $1,500.These checks take 7 days to clear.The company receives checks totaling $1,800.These checks take 4 days to clear.The cost of debt is 9%.What is the firm's disbursement float?

A) $10,500
B) -$8,700
C) $1,800
D) -$10,500