Each time Charles, who has a lisp, says "Mithithippi" or the like, his wife, Evelyn, yells, "Idiot!" However, there is no evidence that Evelyn’s efforts to reduce the frequency of such mispronunciations have been effective. We can therefore conclude that:.
A. Charles’s behavior is due to a neurological problem.
B. Charles’s behavior has not been punished.
C. Evelyn’s efforts to punish Charles’s behavior have actually reinforced it.
D. Charles is lisping deliberately to annoy Evelyn.

B. Charles’s behavior has not been punished.

Explanation:

Each time Charles, who has a lisp, says "Mithithippi" or the like, his wife, Evelyn, yells, "Idiot!" However, there is no evidence that Evelyn’s efforts to reduce the frequency of such mispronunciations have been effective. We can therefore conclude that Charles’s behavior has not been punished.

Negative punishment is a type of punishment which focuses on decreasing the rate of any specific undesired or unwanted behavior from an individual,to enforce this means the removal of certain stimulus from the individual

To reduced a  behavior, there must be a use of strong punishes, withholding reinforcement of the punished behavior or an immediate punishing

to plan an idea out before