Answer:
The solution you are looking for is D.)
Step-by-step explanation:
To determine this, we need to find the amount of miles left they need to travel (243 - 157 = 86). Then we can divide that by the amount of miles per gallon (86 / 21.5 = 4). Because a possible solution to the answer is 4, we know that the dot needs to be solid (filled in), and because the solution can be greater than four, the arrow would be directed to the right / positive side of the line.
