For this case we have the following function:
Where,
g: number of gallons of gas
M (g): number of miles that Danny's truck travels
We know that the maximum capacity is 20 gallons of gas.
Therefore, the maximum distance the truck can travel is given by:
Thus, the domain of the function is:

The range of the function is:
Answer:
A domain and range that are reasonable for the function are:
D. D: 0 ≤ g ≤ 20
R: 0 ≤ M (g) ≤ 340