The answer is C. The slope formula, y2-y1 over x2-x1, which can be remembered as rise over run, can be used to solve. The y2 is 7 as it is the second y and then 1, the first y, is subtracted from it. 7-1=6. After this, you find the second x which is 3, and subtract -6 from it, meaning that you add it as you are subtracting a negative and they cancel out. You now have 3-(-6), or 3+6 on the bottom and 7-1 on the top. 7-1=6 and 3+6=9. The answer is the 6/9 and can be simplified down to 2/3 because of their shared greatest common factor, 3. Hope this helps.