Can someone please help me with this please I’ll give brainliest

Generally, 1. blue is hotter therefore temp and color are correlated, 2. white and blue is lighter then red, color and brightness are related, 3. The larger a star, the brighter and 4. The larger a star the more likely it will be red

The sun's parallax would be 180 degrees, greater than which you can't get.  so a. would be your anwser 

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.