Answer:
A. d = 25; the unit rate is 25 miles per gallon
Explanation:
The point (1, d) on the graph represents (x, y), where,
x = gasoline used = 1 gallon
y = distance = d = 25 miles
That is, (1, d) represents when x = 1, y = 25.
Thus, (1, 25) is the unit rate which is 25miles per gallon.