The vector which can give unit vector along $\mathrm{x}$-axis with $\quad \mathbf{A}=2 \hat{\mathbf{i}}-4 \hat{\mathbf{j}}+7 \hat{\mathbf{k}}, \quad \mathbf{B}=7 \hat{\mathbf{i}}+2 \hat{\mathbf{j}}-5 \mathbf{k} \quad$ and
$\mathbf{C}=-4 \hat{\mathbf{i}}+7 \hat{\mathbf{j}}+3 \hat{\mathbf{k}}$ is
(a) $4 \hat{\mathrm{i}}+5 \hat{\mathrm{j}}+5 \hat{\mathrm{k}}$
(b) $-5 \hat{i}-5 \hat{j}+5 \hat{k}$
(c) $-4 \hat{\mathrm{i}}-5 \hat{\mathrm{j}}-5 \hat{\mathrm{k}}$
(d) $4 \hat{i}-5 \hat{j}-5 \hat{k}$