Which restricted domain would allow you to define the inverse cosine function?

Me answer number 3plz explain how you do it

Which of the following best describes the figure?

In 2014, the three largest economies in the world were (listed in order, from largest): a) the u.s., china, germany. b) the u.s., china, japan. c) china, the u.s., japan. d) china, the u.s., germany.