Action Potentials begin by the actions of both the opening of the voltage gated sodium channels and the closing of the sodium channels, and then opening of the potassium voltage gates channels.
The reaction is:
Cr₃⁺ +3 C₁₀H₈N₂ → [Cr(C₁₀H₈N₂)₃]³⁺
2,2\'-bipyridine is bidentate ligand and neutral. It exhibits two N terminal, thus, it functions as bidentate ligand.
Therefore, three 2,2\'-bipyridine ligand fulfills the six coordination number of Cr₃⁺.
The formula for the complex is [Cr(C₁₀H₈N₂)₃]³⁺
I would say the answer is C the time it takes the planet to complete a path around the sun. I hope I am right and I hope I could help..