Final answer:
The claim about the abundance of low-luminosity stars over high-luminosity ones is supported by the lifespan correlation with luminosity and mass, local neighborhood surveys, and H-R diagram observations showing more common low-luminosity, main-sequence stars.
Thus, the correct option is A.
Step-by-step explanation:
The claim that more low-luminosity stars exist than high-luminosity stars is supported by several observations outlined in the text. Firstly, the fact that low-luminosity stars have longer lifespans is crucial.
The lifetime of a star is directly proportional to its mass and inversely proportional to its luminosity, as indicated by the equation T = 10¹⁰ y, where T is the lifetime, M is the mass, and L is luminosity. This phenomenon explains how low-luminosity stars, being less massive, consume their fuel more slowly, resulting in a longer lifetime and therefore a greater probability of being observed.
Additionally, empirical evidence from surveys like Table 18.1 within our local neighborhood (21 light-years of the Sun) shows that there are significantly more low-mass and low-luminosity stars than those with higher values. Notably, galaxies with blue hues indicate recent star formation with hot, massive, and short-lived stars, while galaxies with a reddish-orange hue suggest the presence of older, long-lasting low-luminosity stars.
Lastly, on the H-R diagram, stars that lie above the main sequence with low temperature but high luminosity are identified as giants or supergiants. This is an extraordinary state that does not represent the commonality of stars, thus supporting the prevalence of main-sequence stars with lower luminosity.
Therefore, the correct option is A.