The reactant that acts as a Lewis Base is A) NH3 B) H20 C) both D) neither

C) both

Explanation:

Lewis base -

Lewis base, are the species that have more electron density hence can easily donate its electron density.

The simple indication to determine, whether a species is a Lewis base or not is to look for negative charge or lone pairs of electrons,

The species having negative charge or lone pairs of electrons, in maximum case, are Lewis bases.

Therefore from the question,

ammonia and water both are Lewis bases.

Because both the species have lone pair of electrons, hence have more electron density and can easily donate its electron density.