Let P be linearity, Q be time-invariance, R be causality and S be stability. A discrete-time system has the input-output relationship,<br>$$y\left( n \right) = \left\{ \matrix{ \matrix{ {x\left( n \right),} &amp; {n \ge 1} \cr } \hfill \cr \matrix{ {0,} &amp; {n = 0} \cr } \hfill \cr \matrix{ {x\left( {n + 1} \right),} &amp; {n \le - 1} \cr } \hfill \cr} \right.$$<br>where x(n) is the input and y(n) is the output.<br>The above system has the properties

Correct Answer: P, S but not Q, R