If the new line is parallel to First Street, it will have the same slope and you can estimate the slope since you know that the line is positive (increasing from left to right) which means that it's positive, so A and B are wrong. If you look at one of the points on the First Street and count how many squares up and over it takes to get to another point on the line, you'll see that the slope is 1/3 so the answer is D