Final answer:
At a four-way stop, if two drivers arrive at the same time, the driver on the right has the right of way, so you should go first.
Step-by-step explanation:
If you reach a four-way stop at the same time as the driver on your left, the general rule of right of way is that the driver on the right-hand side goes first. This means that since the other driver is to your left, you have the right of way and should go first. However, it's always important to proceed with caution and ensure that the other driver is yielding before you proceed. If there's ever any confusion, a courteous wave to the other driver indicating they can go first can help prevent accidents.