Answer:
Star A is a neutron star and star B is a Red giant.
Explanation:
A neutron temperature are extremely hot objects having very high density and appear white in color. They emit large amount of x-rays. A white dwarf is relatively cooler than a neutron star. Black dwarfs emit no light. A red giant star is a cool star. Thus, star A must be a neutron star.
Star B is red in color and has low temperature and extremely bright. Therefore, it must be a red giant star. A blackhole is not visible, a red dwarf is not bright enough to be visible where as a supernova is an event in which a massive star explodes within a short interval of time.
