CJS Electronics has been summarized the discount schedule by two potential suppliers of one type of memory chips as below. CJS's annual usage is 1,000 chips; ordering cost is $30 each time; and annual inventory holding cost per unit is 30% of the unit cost. Which vendor should be selected and which order quantity is the best if CJS wants to minimize total cost? Quantity 1-199 200-499 500+ Vendor A Unit cost ($) 20.00 19.50 19.00 Quantity 1-179 180-349 350-499 500+ Vendor B Unit cost ($) 20.00 19.65 19.25 18.90