Look at the hr diagram below with four stars labeled. the hr diagram is shown with absolute brightness on the vertical axis and surface temperature in degree celsius on the horizontal axis. the dwarf stars are plotted along a slant from coordinates 30,000 and negative 3 to 10,000 and negative 4. the main sequence stars are plotted along a slant from coordinates 20,000 and negative 2 to 2,000 and negative 6. the giants are plotted horizontally from coordinates 5,000 and 2 to 2,000 and 3. the supergiants are plotted horizontally from coordinates 7,500 and 4 to 2,500 and 4. four stars are plotted: a is at 20,000, negative 4, b is at 2,500, negative 4, c is at 5,000, 2, and d is at 6,000, 4. which statement is correct about star a and star c? they have the same color because they are neighboring stars. they have the same brightness because they are neighboring stars. they have different colors because they have different temperatures. they have different brightness because they are the same size.