If Circle Is a Structure Tag, the Statement: Circle Dosomething

If Circle is a structure tag, the statement: Circle dosomething (circle c2)
Can be the header line for a function that ________.

A) determines and returns the area of a circle
B) takes a Circle structure as a parameter, does something, and returns a Circle structure
C) operates on a constant reference to a Circle structure
D) takes two Circle parameters and does something
E) None of these