The correct option is (b) 20.6
Easy explanation: Given the point is in 2^nd quadrant. Since here distance from side view and top view is asked for that we need the distance between the front view and side view (10+10); front view and top view (10-15) and these lines which form perpendicular to each other gives needed distance, answer is √(20^2+5^2 ) = 20.6 units.