The purpose of a buffer is to
(a) imply the negative news instead of stating it explicitly.
(b) make it easier to change your mind later.
(c) justify your decision for the bad news.
(d) lessen the effect of negative news.
(e) state the obvious to pave the way for the bad news.

The answer is:

(D) lessen the effect of negative news

Explanation:

In chemistry, a buffer is a solution form by a  weak acid and its conjugate base, or a weak base and its conjugate acid that can resist changes in pH when an acid or base is added to it, as it neutralizes them.

So, as it neutralizes the effect of the acid or bases in pH, the chosen answer for the question is that a buffer is to lessen the effect of negative news.

can you attach a picture of the lettuce? : )