Choose the correct statement(s) about a conductivity cell and the conductivity of a solution.

1. AThe cell constant $G^{\ast }=l/A$ depends only on the geometry of the electrodes and not on the solution placed in the cell
2. BThe conductivity of a solution is numerically equal to the conductance of a $1\mathrm{cm}$ cube of the solution held between electrodes of area $1\mathrm{c}{\mathrm{m}}^2$ placed $1\mathrm{cm}$ apart
3. CIn SI units conductivity is expressed in $\mathrm{S}{\mathrm{m}}^{-1}$, and $1\mathrm{S}\mathrm{c}{\mathrm{m}}^{-1}=100\mathrm{S}{\mathrm{m}}^{-1}$
4. DThe cell constant of a given cell increases when the solution in it is diluted