The correct answer is a negative correlation. This means that as one increases, the other decreases. In this case, as the age of a car increases, its value decreases. On a graph this will look like a line going down from the top left to the bottom right. A positive correlation would be the opposite (as one increases, so does the other). A constant correlation means that something is increasing or decreasing at a steady rate (since we don't know how much a car's value depreciates each year, we can't determine if it's a constant relationship).
