Hydraulics Unlimited had the following 12 months of data on purchasing costs and number of purchase orders. Month January Purchasing Cost $57,226 Number of Purchase Orders 457 February 93,178 745 March 70,925 567 April 54,985 432 May 70,232 561 June 90,259 723 July 78,963 631 August 72,687 582 September 86,234 689 October 94,255 753 November 74,891 598 December 80,199 642 Using the high-low method, what is the variable rate for purchasing cost based on the number of purchase orders? (Round to the nearest whole dollar. Oa. $150 Ob. $175 c. $122 Od. $102 I'm D