The unit step response of a discrete-time, linear, time-invariant system is
\[
y[n]=\left\{\begin{array}{rl}
0, & n<0 \\
1, & n \geq 0 \text { and } n \text { even } \\
-1, & n \geq 0 \text { and } n \text { odd }
\end{array}\right.
\]
Which of the following statements about the system is true?
- the system is anti-causal
- the system is memoryless
- the system is bounded-input, bounded-output $\text{(BIBO)}$ stable
- there is not enough information to determine $\text{(BIBO)}$ stability
- none of the above