Ophelia imports glass ornaments from Norway. She prepares accounts to 30 June each year. In the year ending 30 June 20X9 she records the following totals for trading transactions:

Sales 83 722 Purchases 65 277 Special charges for safety packaging 604 Sales returns 426 Purchases returns 291 Opening stock at 1 July 20X8 was £5799. Closing stock at 30 June 20X9 was £5904. What is Ophelia's gross profit for the year?

a) 18 084

b) 18437

c) 18 663

d) 17 811.