C&A purchases fertilizer for its lawn-care business from a supplier who charges $30 per order and $60 per case. Each case consists of five bags of fertilizer. C&A needs 2000 bags of fertilizer a year. C&A's annual holding costs are 30%. What is C&A's holding cost per case per year? please show steps
A) $15
B) $18
C) $10
D) $5