Which statement best describes the events responsible for the phase represented by the letter B in the figure?

A. the opening of sodium channels
B. the opening and closing of sodium channels
C. the opening of potassium channels
D. the closing of sodium channels and the opening of potassium channels
E. the opening of potassium channels and the closing of sodium channels

Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's plasma membrane. Sodium channels are the founding members of ion channel super-family that includes voltage-gated calcium channels, TRP channels, voltage-gated, inward rectifying, and two-pore-domain potassium channels, and cyclic nucleotide-regulated CNG and HCN channels. When the neuron becomes stimulated the voltage gated sodium channels begin to open and the membrane potential begins to slowly depolarizes and sodium enters the cell down its concentration gradient.