Beechtree Corporation sells chewing gum and during January they ran production machines for 28,000 hours total and incurred $14,000 in maintenance costs. During July they ran production machines for 18,000 hours total and incurred $6,200 in maintenance costs. Based on this data, what is the variable maintenance cost per machine hour? O A. $0.44 per machine hour OB. $0.78 per machine hour OC. $0.34 per machine hour OD. $2.8 per machine hour