Please explain the calculations

The Police Department of a given city received an appropriation in the amount of $8,000,000 for the fiscal year ended June 30, 2014. During the month ended July 31, 2013, the following transactions occurred: (a) purchase orders were issued in the amount of $500,000; (b) purchase orders, related to (a) above, were filled in the amount of $460,000; the related invoice amount was $463,000; invoices were paid in the amount of $450,000; (c) salaries were accrued and paid in the amount of $480,000. The balance available for the police department as of July 31, 2013 is:

A) $7,010,000. B) $7,017,000. C) $7,000,000. D) $7,007,000.

Answer: B