Which statement is true about the single abstract metho…

Which statement is true about the single abstract method of the java.util.function.Function
interface?

A.
It accepts one argument and returns void.

B.
It accepts one argument and returns boolean.

C.
It accepts one argument and always produces a result of the same type as the argument.

D.
It accepts an argument and produces a result of any data type.

Explanation:
http://winterbe.com/posts/2014/03/16/java-8-tutorial/ (functions)