. A wave is represented by the equation y = A sin(10rx + 15rt + p/3), where x is in meters and t is in seconds. The expression represents

• (A):a wave travelling in the positive x – direction with a velocity 1.5 m/s
• (B):a wave travelling in the negative x – direction with a velocity 1.5 m/s
• (C):a wave travelling in the negative x – direction having a wave-length –0.2m
• (D):a wave travelling  in the positive x – direction having a wavelength 0.2m