A voltage $1000 \sin \omega t$ Volts is applied across $YZ$. Assuming ideal diodes, the voltage measured across $WX$ in Volts is
1. $\sin \omega t$
2. $(\sin \omega t + \sin \omega t ) / 2$
3. $(\sin \omega t - \sin \omega t ) / 2$
4. $0$ for all $t$