d
$(d)$ Polar Aprotic Solvents : Aprotic solvents are those solvents whose molecules do not have a hydrogen atom that is attached to an atom .of an electronegative element. A number of polar aprotic solvents have come into wide use by chemists because they are especially useful in $S_{N^2}$ reactions. Several examples are the following

All of these solvents $(DMF, DMSO, DMA,$ and $HMPA)$ dissolve ionic compounds, and they solvate cations very well. They do so in the same way that pro tic solvents solvate cations : by orienting their negative ends around the cation and by donating unshared electron pairs to vacant orbitals of the cation