Consider a wave whose profile at $t=0$ is given by a function $x|f(x).$ The same wave causes, at position $x=0m,$ displacement as a function of time given by a function $t|g(t).$ Which way is this wave moving? $($A$)$ left $($C$)$ it could be either $($B$)$ right $($D$)$ these two profiles are incompatible