Which one of the following represents a wave ?

Three waves y_(1), y_(2) ,y_(3) are given by y_(1)= A sin (Kx- omegat), y_(2) A= sin (Kx+ omega t) and y_(3) = A sin (Ky- omega t) . Which one of the following represents wave ?

Which of the following represents a wave?

Which of the following represents a wave