His quote is important so we learn our lessons from the past so we don't repeat them in the future. The post-WWII generation needs to learn about the tragedy of the Holocaust along with how Hitler and the Nazis were able to rise to power, and we need to know how to act when we see parallels to this in the modern world.
Letter D is the answer. Because you can be more interested into other things besides dancing.
That would be considered A. explicit memory. Hope this helps!
The picture is unclear message me so i can answer