Calculate the Angle Between $\mathbf { a }$ And $\mathbf { b }$

Multiple Choice

Calculate the angle between $\mathbf { a }$ and $\mathbf { b }$ (correct to the nearest degree) .
$$\mathbf { a } = 9 \mathbf { i } - 8 \mathbf { j } , \mathbf { b } = - 7 \mathbf { j } + \mathbf { k }$$
Select the correct answer.

A) $98 ^ { \circ }$
B) $49 ^ { \circ }$
C) $39 ^ { \circ }$
D) $59 ^ { \circ }$
E) None of these