Company A leases a copying machine on a monthly basis. The lease agreement requires a fixed rental fee each month in addition to a charge per copy. In September, Company A paid $162 for rent and 2400 copies. In October, Company A paid $195 for rent and 3500 copies. What is Company A's variable cost per copy?
Select one:
a. $0.06
b. $0.04
c. $0.03
d. $0.01