The correct answer here is that a buffer D. donates H+ ions when conditions become too basic and accepts H+ ions when conditions become too acidic....

Does a buffer donate H or OH?

In a solution, a buffer minimises the changes in pH arising from the addition of small amounts of acid (H+) or alkali (OH-). It does this because a buffer is a solution containing a weak acid and its conjugate base.

Do buffers accept or donate?

A buffer is rather simple by definition: it's a solution that contains an acid matched with an equal-strength, or conjugate, base. Remember that acids donate protons, and bases accept protons. ... A buffering action occurs here because water can dissociate into a strong acid and a strong base, but balance each other out.