Kuczenski Corporation's Cost Formula for Its Manufacturing Overhead Is $45,700

Kuczenski Corporation's cost formula for its manufacturing overhead is $45,700 per month plus $53 per machine-hour. For the month of March, the company planned for activity of 6,200 machine-hours, but the actual level of activity was 6,150 machine-hours. The actual manufacturing overhead for the month was $373,630.
-The activity variance for manufacturing overhead in March would be closest to:

A) $670 U
B) $670 F
C) $2,650 F
D) $2,650 U