Find, Correct to the Nearest Degree, the Angle Between the Planes

Multiple Choice

Find, correct to the nearest degree, the angle between the planes.
$$x + y - z = 1,10 x - 15 y + 20 z = 5$$

A) $122 ^ { \circ }$
B) $12 ^ { \circ }$
C) $22 ^ { \circ }$
D) $102 ^ { \circ }$
E) none of these