What is 2+ (-3) equal to -1?

A. Because it is 3 units to the left of 2 on a horizontal number line

B. Because it is 3 units to the right of 0 on a horizontal number line

C. Because it is 3 units to the left of 0 on a horizontal number line

D. Because it is 3 units to the right of 2 on a horizontal number line