Pearse 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 December, the kennel budgeted for 5,300 tenant-days, but its actual level of activity was 5,320 tenant-days. The kennel has provided the following data concerning the formulas used in its budgeting and its actual results for December:

Data used in budgeting:

	Fixed element per month	Variable element per tenant-day
Revenue		$31.80
Wages and salaries	$4,300	$7.80
Food and supplies	900	12.60
Facility expenses	8,700	4.80
Administrative expenses	7,700	0.60
Total expenses	$21,600	$25.80

Actual results for December:

Revenue	$109,080
Wages and salaries	$23,630
Food and supplies	$36,803
Facility expenses	$19,380
Administrative expenses	$9,166

The net operating income in the flexible budget for December would be closest to:

a. $20,007

b. $20,101

c. $10,200

d. $10,320