Data concerning Nelson Company's activity for the first six months of the year appear below: Based on the high-low method, the estimated variable cost per machine hour is: Machine Electrical Month Hours (X) Cost (V) January 4,000 $3,120 February 6,000 $4,460 March 4,800 $3,500 April 3,800 $2,850 May 3,600 $2,900 June 4,200 $3,200 A. 50.671 B. $0.709 O C 50.732 OD. $0.650