The signal $x(t)$ is described by

$x(t)=\left\{\begin{array}{ll}

1 & \text { for }-1 \leq t \leq+1 \\

0 & \text { otherwise }

\end{array}\right.$

Two of the angular frequencies at which its Fourier transform becomes zero are

- $\pi, 2 \pi$
- $0.5 \pi, 1.5 \pi$
- $0, \pi$
- $2 \pi, 2.5 \pi$