If PQ = QR, then the difference of each of the x-, y-, and z-coordinates between PQ and between QR would be identical. P - Q: x = 6 - 3 = 3, y = 0 - 2 = -2, z = 4 - 1 = 3 Subtract these differences from Q again to get the coordinates for R: Rx = 3 - 3 = 0 Ry = 2 - (-2) = 4 Rz = 1 - 3 = -2 So the coordinates of R are (0, 4, -2), which is Choice A.
