Perla Kennel uses tenant-days as its measure of activity; an animal housed in the kennel for one day is counted as one tenant-day. During March, the kennel budgeted for 2,270 tenant-days, but its actual level of activity was 2,230 tenant-days. The kennel has provided the following data concerning the formulas used in its budgeting and its actual results for March: Data used in budgeting:

	Fixed element per month			Variable element per tenant-day
Revenue		?		$	36.10
Wages and salaries	$	4,770		$	8.00
Food and supplies		1,850			9.60
Facility expenses		9,550			6.20
Administrative expenses		8,200			0.90
Total expenses	$	24,370		$	24.70

Actual results for March:

Revenue	$	79,933
Wages and salaries	$	22,415
Food and supplies	$	23,773
Facility expenses	$	22,471
Administrative expenses	$	10,262

The activity variance for wages and salaries in March would be closest to:

$320 F

$320 U

$515 F

$515 U