After the action potential passes through an axon, gated potassium channels open and allows potassium ions to flow out.
This question had choices. These are the missing choices.
A) Scientists made careful observations of behavioral patterns.
B) The DNA mutation rates for both species was calculated and compared.
C) Scientists made a detailed analysis of the fossilized bones of each species.
D) The enzyme activity of each species was studied to determine similarities in metabolism.
My answer:
C) Scientists made a detailed analysis of the fossilized bones of each species.
This determination is the only feasible thing to do since dinosaurs are long dead and choices A, B, and D requires the subjects to be alive.
The answer is B I believe!