An electromagnetic wave has an electric field given by

E$($y$,$t$)=[2\mathrm{.}50105$V$/$mcos$($ky$(1\mathrm{.}3501013$rad$/$s$)$t$)]$k$^$E$($y$,$t$)=[2\mathrm{.}50105$V$/$mcos$($ky$(1\mathrm{.}3501013$rad$/$s$)$t$)]$k$^.$

In which direction is the wave traveling?

In $+$x$-$directionIn $+$y$-$direction

In $+$z$-$direction

In $-$x$-$directionIn $-$y$-$directionIn $-$z$-$direction