The U.S. government protects fish, a common resource, by A. heavily taxing competing industries. B. subsidizing the fishing industry. C. selling fishing licenses and regulating fish lengths. D. None of the above is correct.

The U.S. government protects fish, a common resource, by selling fishing licenses and regulating fish lengths

Explanation:

When there is regulation about a particular goods, it reduces the rate the availability of such goods is abused, US government could actually protect fish through licensing and regulation of the type to be sold including there length which ensures the protection of the juvenile.

Na-K channels

Explanation:

Brief sequential change in the membrane potential of excitable cells after stimulus is called action potential whereas membrane potential represent charge difference across the membraneIn a typical neuron cell, membrane potential of cytoplasm is negative at rest and hence called resting membrane potential Resting membrane potential of excitable cells is established by Na+ K+ pump and maintained by K+ leaky channels at rest Phases of action potential includes: depolarization, repolarization, hyperpolarization and resting membrane potential Depolarization starts when a threshold stimulus is applied on a neuron when via Na+ mechanically operated channels that trigger action potential Depolarization of membrane potential is due to influx of Na+ via voltage gated Na+ channels Repolarization starts with the efflux of K+ by the opening of voltage gated K+ channels, voltage gated K+ channels starts to open when voltage gated Na+ channels becomes occurs due to excessive efflux of K+ by voltage gated K+ channels Additional efflux of K+ occurs due to slow inactivation of voltage gated K+ channel