Eberley corporation's cost formula for its manufacturing overhead is $25,700 per month plus $10 per machine-hour. for the month of july, the company planned for activity of 5,900 machine-hours, but the actual level of activity was 5,920 machine-hours. the actual manufacturing overhead for the month was $86,800. the spending variance for manufacturing overhead in july would be closest to:
a. $2,100 u
b. $1,900 f
c. $1,900 u
d. $2,100 f