The NMDA receptor is a __ receptor that when it binds its neurotransmitter allows ___ entry into the cell, which can promote changes at the synapse that aid in learning and memory but can cause postsynaptic cell death if the receptor is activated for a prolonged time period.

The NMDA receptor is a ionotropic receptor that when it binds its neurotransmitter allows calcium entry into the cell, which can promote changes at the synapse that aid in learning and memory but can cause postsynaptic cell death if the receptor is activated for a prolonged time period.

Explanation:

NMDA receptors is an ionotropic glutamate receptor, which has functions in neuroplasticity, but also in excitotoxicity. The receptors are activated by a power differential, when Magnesium ions (Mg2 +) come into contact. This step allows the sodium (Na +), calcium (Ca2 +) ions (these in less quantity) and potassium (K +) ions to flow. The flow of calcium ions, specifically, is essential to enhance the processes of synaptic plasticity or brain plasticity. NMDA receptors play an important role in the development of pain, particularly neuropathic pain.

I think it's c due to the fact that they point out the previous highest point