Action potentials move along axons A) more slowly in axons of ...

[geoffrey]

Action potentials move along axons
A) more slowly in axons of large than in small diameter.
B) by the direct action of acetylcholine on the axonal membrane.
C) by activating the sodium-potassium "pump" at each point along the axonal membrane.
D) more rapidly in myelinated than in non-myelinated axons.
E) by reversing the concentration gradients for sodium and potassium ions.

[j_sun]

I recall doing this last year, it's D, bye bye!