Best Shingle's budgeted manufacturing costs for 50,000 squares of shingles are: I Fixed manufacturing costs $12,000 Variable manufacturing costs $16.00 per square Best produced 40,000 squares of shingles during March. How much are budgeted total manufacturing costs in March using a flexible budgeting approach? (A) $652,000 $640,000 C) $812,000 $800,000