The mass of a star can be determined by studying D) binary star systems.
Although there may be other ways to determine the mass of a star, this is the most common one which is widely used all over the world when it comes to measuring objects in the universe.
Some examples of limiting factors are biotic, like food, and mates. Limiting factors can affect the populations of both plant and animal species. An invasive species is an organism that is not indigenous, or native, to a particular area.
-look at the obvious
-analyze the artwork
-decide on an interpretation
-make a judgement call