On an Average Day,a Company Writes Cheques Totaling €1,500

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

A) €-7,200
B) €-1,800
C) €1,800
D) €10,500
E) None of the above.