# Question #59d6d

$D .$ is not always correct............
Since $A . , B . , C . ,$ are satisfied, there remains $D .$ In the (high temperature) melt, discrete positive and negative ions exist which are no longer constrained by the phase, and can move relative to each other, and may therefore conduct electricity. Sometimes we can form aqueous solutions of soluble ionic compounds, in which the individual ions are solvated, and such a solution may also be electrically conductive.