Thomasson Air uses two measures of activity, flights and passengers, in the cost formulas in its budgets and performance reports. The cost formula for plane operating costs is $36,180 per month plus $2,046 per flight plus $1 per passenger. The company expected its activity in April to be 78 flights and 228 passengers, but the actual activity was 77 flights and 233 passengers. The actual cost for plane operating costs in April was $191,500. The activity variance for plane operating costs in April would be closest to:

a	$4,496 U
b	$2,041 U
c	$2,041 F
d	$4,496 F