Calcium Calmodulin-Dependent Protein Kinase II (CaMKII) Is Necessary for LTP

Calcium calmodulin-dependent protein kinase II (CaMKII) is necessary for LTP because

A) once activated by calcium, it can auto-phosphorylate and activate itself after calcium concentration lowers.
B) once activated, it leads to the insertion of NMDA receptors to the postsynaptic membrane.
C) once activated, it leads to the removal of AMPA receptors to the postsynaptic membrane.
D) once activated, it leads to gene expression.
E) it is necessary for glutamate binding to the NMDA receptor.