Vitamin D is sometimes called the sunshine vitamin because a. it is available in fresh orange juice b. exposure to sunlight converts a precursor form to vitamin D c. it can be destroyed by exposure to sunlight d. it is the yellow-orange color of the sun

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

the statements that apply here about binary star system are

"have stars that might appear to wobble"

"often have one star that is brighter than other"

a binary star is a star system consisting of two stars revolving around their common barycenter. systems of two or more stars are called multiple star systems.