Answer: The answer is D
Explanation:
Additive Identity is an identity element (such as 0 in the group of whole numbers under the operation of addition) that in a given mathematical system leaves unchanged any element to which it is added.
For example: 2 + 0 = 2. 0 + 5 = 5.
So, therefore the answer is 0
Hope this is helps and you undertand this :)