There are different star systems. Binary star systems consist of two stars. Multiple star systems consist of two or more stars. The meaning of star system is "A small number of stars."
I think it's either A) a group of hundreds of stars, or B) a group of two or more stars. I would assume it's B), but i could be wrong.
Hope this helps!
The answer is B because It helps plants absorb energy and get their nutrients from the sunlight
ATP or the Adenosine Triphosphate is referred to as the basic energy unit of the body. In the case of doing an exercise, what happens is that, the more someone increases his or her activity, the more energy is required and the body should compensate for this need. Therefore, the answer for this would be option D.