Use the high-low method for the following information: Month ... .Cost.......... Hours January...............$4,400........ 3,500 February........... $8,000........ 7,000 March.............. $11,000...... 9,500 April........ $9,000 .........8,500 May............ . $5,500......... 7,700 The variable cost per unit is: A) $0.80 B) $1.07 C) $1.10 D $2.20