Answer:
The correct answer is A.
Explanation:
Giving the following information:
Dubberly Corporation's cost formula for its manufacturing overhead is $31,100 per month plus $50 per machine-hour. For March, the company planned for activity of 8,000 machine-hours, but the actual level of activity was 7,930 machine-hours. The actual manufacturing overhead for the month was $454,110.
activity variance for manufacturing overhead= (50*8000) - (454,110 - 31,100)= 23,010 unfavorable.