A delivery truck driver charges a fixed base price of $6 for 2 miles. After 2 miles, he charges an additional $2 for every mile. After 6 miles, he charges an additional $4 for every mile. Describe the cost of the delivery truck between 1 mile and 2 miles.

A.
The cost of the delivery truck between 1 mile and 2 miles is constant.
B.
The cost of the delivery truck between 1 mile and 2 miles cannot be determined from the given information.
C.
The cost of the delivery truck between 1 mile and 2 miles is increasing.
D.
The cost of the delivery truck between 1 mile and 2 miles is decreasing.