See the picture to you. its what you use to answer the question.

what can be concluded about the initial mass of a blue main sequence star compared to a red main sequence star?

blue main sequence stars had a greater initial mass.

red main sequence stars had a greater initial mass.

blue main sequence stars have the same initial mass as red main sequence stars.

initial mass comparisons cannot be made between blue and red main sequence stars.

Blue main sequence stars had a greater initial mass.

Explanation:

Color as indicator of temperature. Blue represents a hot a star that is a star with very high temperature. On the other hand, a red color star represents a cool star. The initial mass of a blue main sequence must be greater than the initial mass of a red main sequence star. For high temperature, more fuel must be burnt which means greater initial mass. A blue main sequence star is a hot star and must have greater initial mass, so it burns more fuel and has high temperature as compared to the red main sequence star.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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