Nitrol Corporation manufactures brass vases using a standard cost system with standard machine-hours as the activity base for overhead. The following information relates to vase production at Nitrol for last year:

	Estimated for year	Actual results for year
Variable overhead	$58,500	$61,910
Fixed overhead	$292,500	$289,900
Machine-hours	117,000	121,000

The standard machine-hours per vase is 1.45. Last year Nitrol produced 96,000 vases.

What was Nitrol's variable overhead rate variance for last year?

a. $12,000 Unfavorable

b. $810 Unfavorable

c. $600 Favorable

d. $1,410 Unfavorable