ABC Company reported the following information about the production and sales of its Rubber product:

Direct materials used	$32,000
Direct labour	$20,000
Variable factory overhead	$12,000
Fixed factory overhead	$16,000
Variable selling and administrative expenses	$ 4,000
Fixed selling and administrative expenses	$ 6,000
Beginning inventories	none
Ending inventories	600 units
Sales ($45 per unit)	$63,000

Required: Please provide the below criteria

a) Variable cost per unit

b) The cost of goods sold under variable costing

c) The contribution margin under variable costing

d) The operating income (loss) under variable costing