Answer
$A$ and $B$ have the same direction.
Work Step by Step
If $A$ and $B$ do not have the same direction, the vectors $A$, $B$ and $C$ form a triangle. But, in a triangle each side is smaller than the sum of the other two sides. That is:
C $\lt$ A + B, A $\lt$ B + C and B $\lt$ A + C.
So, if C = A + B, than $A$ and $B$ have the same direction.
