The inventory records for Radford Co. reflected the following

Beginning inventory @ May 1	100 units @ $4.00
First purchase@ May 7	300 units @ $4.40
Second purchase@ May 17	500 units @ $4.60
Third purchase@ May 23	100 units @ $4.80
Sales @ May 31	900 units @ $7.80

Determine the amount of gross margin assuming the weighted average cost flow method.

a	$3,015
b	$2,412
c	$1,314
d	$2,610