At a point in space, let the field and potential be having values $E$ and $V$ respectively. Out of the following assertions which one(s) is/are correct?

The electric field is $E=-\frac{dV}{dx}$

If $\mathrm{V}=0,$we can not say $\mathrm{E}$ must be zero, we say only $\mathrm{E}$ may be zero.

If  $V\ne 0$, E may  be zero .For example, inside the conductor $\mathrm{E}=0,$ but $\mathrm{V}\ne 0$

If $E\ne 0$, V may be zero when two equal and opposite charges separated by a distance and at the midpoint in between the charges field is non-zero but potential is zero.

Hence the correct answer is 3