(Appendix 5A) One of Matthew Corporation's Competitors Has Learned That

(Appendix 5A) One of Matthew Corporation's competitors has learned that Matthew has a total expense per unit of $1.50 at the 15,000 unit level of activity and total expense per unit of $1.45 at the 20,000 unit level of activity. Assume that the relevant range includes all of the activity levels mentioned in this problem.
-What would be the competitor's prediction of variable cost per unit for Matthew Corporation?

A) $1.30
B) $0.77
C) $1.50
D) $1.45