Which of the Following Function Is NOT a Possible Wave

Which of the following function is NOT a possible wave equation? A and c are constants.The other symbols have their usual meaning.

A) y(x,t) = 1/(x - vt)
B) y(x,t) = A e^-vxt/c
C)
D) y(x,t) = A cos (kx) sin (ωt)
E) y(x,t) = A sin(kx + ωt)