A little help:)

hey everyone,how is your preparation for the sat exam?
I hope that you prepared well and studied well for Saturday.
To help i will post sat questions from my account for the next two days .


Read the following SAT test question, then write your answer.

* function f of (2 times n) = 2 times function f of n for all integers n
* function f of 4 = 4

If function f is a function defined for all positive integers n, and function f satisfies the two conditions above, which of the following could be the definition of function f?
Answer Choices

* (A) function f of n = n - 2
* (B) function f of n = n
* (C) function f of n = 2 x n
* (D) function f of n = 4
* (E) function f of n = (2 x n) - 4
I will write the answer down but please don't cheat okay:)
(answer is choice (B))
I really hope that i helped you and good luck on Saturday :)