Glassing Clinic uses client-visits as its measure of activity. During September, the clinic budgeted for 3,735 client-visits, but its actual level of activity was 3,695 client-visits. The clinic has provided the following data concerning the formulas to be used in its budgeting:

	Fixed element per month			Variable element per client-visit
Revenue				$	29.60
Personnel expenses	$	23,400		$	6.60
Medical supplies		1,105			6.30
Occupancy expenses		4,065			3.90
Administrative expenses		3,075			2.00
Total expenses	$	31,645		$	18.80

The activity variance for net operating income in September would be closest to:

$3,592 U

$432 F

$432 U

$3,592 F