This question starts by saying there is a circle centered on the origin (0,0) and with a radius of two. Using the unit circle, you can determine your initial points, (0,1), (sqrt(3)/2,1/2), (sqrt(2)/2,sqrt(2)/2), (1/2,sqrt(3)/2), (1,0) (note: any mixture of negatives will still be true for points on the circle). As the unit circle has a radius of 1, to get these points on your circle, all you need to do is multiply your x and y values by 2, giving you the points (0,2), (sqrt(3),1), (sqrt(2),sqrt(2)), (1,sqrt(3)), (2,0), and all negative variations. Of all of these, the one that matches an answer choice is (sqrt(3),1), or answer choice C.