Two sinusoidal signals of the same frequency are displayed on a dual-trace oscilloscope. One complete cycle of each signal covers 6 cm of the horizontal scale and the starting point of the horizontal scale and the starting point of the two signals are separated by 0.5 cm. The phase difference between the two signals in degrees is

(a) 30 (b) 45 (c) 60 (d) 90

(a) 30 (b) 45 (c) 60 (d) 90