The absolute magnitude of a

describes its actual brightness
describes how bright the star looks from earth
changes according to the observer’s location on earth
is multiplies by the apparent magnitude to determine distance

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

real, smaller and upside-down.   so the answer should be b.