A plane wave propagating in air with $\overrightarrow{E}=(8\hat{a}_x+6\hat{a}_y+5\hat{a}_z)e^{j(\omega t+3x-4y)}\:V/m$ is incident on a perfectly conducting slab positioned at $x\le0$ . The $\overrightarrow{E}$ field of the reflected wave is
- $(-8\hat{a}_x-6\hat{a}_y-5\hat{a}_z)e^{j(\omega t+3x+4y)}\:V/m$
- $(-8\hat{a}_x+6\hat{a}_y-5\hat{a}_z)e^{j(\omega t+3x+4y)}\:V/m$
- $(-8\hat{a}_x-6\hat{a}_y-5\hat{a}_z)e^{j(\omega t-3x-4y)}\:V/m$
- $(-8\hat{a}_x+6\hat{a}_y-5\hat{a}_z)e^{j(\omega t-3x-4y)}\:V/m$