Answer:
A. When adding a negative number, you move down
Step-by-step explanation:
Actually, according to transformation of functions, there's two types of transformation, those that only involve translation, and those that change the dimension of the function.
In this case, modelling a solution to an addition problem, we know that adding a negative number, the function will move downs, because in that case we will be transformation or "changing" the y-variable, that's why it will move vertically.
Therefore, the right answer is A.
