If a = 3 + b, which of the following is true?

Question

See: Nova GRE Math Bible. Page-$234$.

Problem #06

If a = 3 + b, which of the following is true?

(I) a > b + 2.5
(II) a < b + 2.5
(III) a > 2 + b

(A) I only
(B) II only
(C) III only
(D) I and II only
(E) I and III only

The given answer is (A), (C), and (D).

How come?

My calculation was (E).

Answer 1

Here is a snippit from the link you included.

Answer 2

Your answer is right. A good way to find out is giving values. I always do that. In India we call it the jugaad method. Let $b=0$ and $a=b+3=3$. Now you can just test the values.