PLEASE help nobody has answered my recent questions!! which sentence is best structured to make a direct statement about one idea?
A. NASA is known for sending humans to the moon, but the famous space program has also send in a name spaceship to Mars.
B. some people think that nasty should focus on exploring the universe, but others believe that building a colony on the moon is the most important goal, not even though it will be difficult.
C. the mission of NASA is to explore outer space.
D. 4 since NASA was founded, it has sent more than 250 astronauts into space. ​

C. The mission of NASA is to explore outer space

Explanation:

All the other questions either show two points of view or two or more ideas.C only contains one idea

  this riddles' answer is library.

  the "leaves" are a reference to the books' pages that the library contains; the branches are a network of libraries that connect multiple libraries' collections, resources, and items in a system of a common database, integrating them; the branches' organization are a useful management tool for coordinating the multiple collections many libraries have.

where is the sentence at?