The aprotic solvent is A. H2O B. C6H6 C. HF D. NH3

H2O
C6H6
HF
NH3

The correct answer is $\boxed{\text{B}}$, $\ce{C6H6}$, benzene.

Aprotic solvents are solvents that do not contain a hydrogen atom bonded to an electronegative atom, such as oxygen or nitrogen. This means that they do not have a hydrogen bond donor, and they are therefore not able to participate in hydrogen bonding interactions with other molecules.

Water, $\ce{H2O}$, is a protic solvent because it contains a hydrogen atom bonded to an electronegative oxygen atom. This hydrogen atom can participate in hydrogen bonding interactions with other molecules, such as alcohols and acids.

Hydrogen fluoride, $\ce{HF}$, is also a protic solvent because it contains a hydrogen atom bonded to an electronegative fluorine atom. This hydrogen atom can participate in hydrogen bonding interactions with other molecules, such as alcohols and acids.

Ammonia, $\ce{NH3}$, is a protic solvent because it contains a hydrogen atom bonded to an electronegative nitrogen atom. This hydrogen atom can participate in hydrogen bonding interactions with other molecules, such as alcohols and acids.

Benzene, $\ce{C6H6}$, is an aprotic solvent because it does not contain a hydrogen atom bonded to an electronegative atom. This means that it does not have a hydrogen bond donor, and it is therefore not able to participate in hydrogen bonding interactions with other molecules.