When Considering the Role of Sleep for Memory Consolidation, Why

When considering the role of sleep for memory consolidation, why might studies show that there is weakening of synapses in terms of size and physiological strength?

A) Sleep resets synapses globally, so that the minority that were strengthened by wakeful experience can stand out.
B) Sleep actually strengthens rather than weakens synapses, and this is how consolidation of memories can occur.
C) Sleep has very limited effects on synapses, with the effects described in this question only occurring in the hippocampus.
D) Sleep has no effect on synapse strength, and consolidation occurs via other mechanisms.