How Can Memory Be Affected When a Sufficient Amount of Sleep

How can memory be affected when a sufficient amount of sleep is not attained?

A) The immune system weakens without enough sleep,so all the extra brain power is needed to help jump-start the immune system.
B) Without enough sleep,plaques are able to form in the brain,which clog transmissions of signals between the neurons.
C) Sleep is needed only for our bodies to recover and rejuvenate;sleep does not affect our memory.
D) A deficient amount of sleep causes the immune system to develop microvascular infarcts and inflammation,which causes a delay in our memories.