Figure shows four electronic switches $(i), (ii), (iii)$ and $(iv)$. Which of the switches can block voltages of either polarity $($applied between terminals $a$ and $b)$ when the active device is in the $OFF$ state?
1. $(i), (ii)$ and $(iii)$
2. $(ii), (iii)$ and $(iv)$
3. $(ii)$ and $(iii)$
4. $(i)$ and $(iv)$