Let $x = - 7$ And $z = - 10$ Find $$B = x - z$$

Multiple Choice

Let $x = - 7$ and $z = - 10$ . Find $$B = x - z$$

A) $B = - 17$
B) $B = - 3$
C) $B = 3$
D) $B = 17$
E) none of these