The following data are from Burton Corporation, a manufacturer, for the month of September:

	Direct materials used	$	135,000
	Supervisors’ salaries		6,000
	Machine operators’ wages		200,000
	Sales office rent and utilities		22,000
	Machine depreciation		35,000
	Secretary to the Chief Executive Officer's salary		3,000
	Factory insurance		15,000

Compute the prime costs.

a. $344,000

b. $256,000

c. $135,000

d. $335,000