Professor wallace studies memory in people who have had strokes. professor hansen studies people who claim to have clear memories of events that happened over three decades ago. such research on the extremes of memory: a. us to understand how memory works. b.explains how consciousness works. c.is not useful to psychologists who study normal memory. d. make us realize that it is impossible to study memory

The correct answer is c) is not useful to psychologists who study normal memory.

Explanation:

Since both researches study extraordinary cases - one related to poor functioning of the memory due to physical conditions and the other related to an uncommonly acute performance, they are useless to the understanding of how memory works in normal conditions. Thus, option A would be incorrect.

Option B confuses memory with consciousness, which are very different things and option D is a false conclusion.