The cartesian equation of the plane $\overrightarrow{r}.(\hat i\;+\hat j-\hat k)\;=2$ is ____________.

Question

$\begin{array}{1 1} (A)\; x+y-z-2=0 \\ (B)\; x-y-z-2=0 \\ (C)\; x+y+z+2=0 \\ (D)\; x-y-z+2=0 \end{array} $