Find the Angle Between the Two Planes $\begin{array} { l } 3 x - 4 y + 5 z = 6 \\x + y - z = 2\end{array}$

Multiple Choice

Find the angle between the two planes. $\begin{array} { l } 3 x - 4 y + 5 z = 6 \\x + y - z = 2\end{array}$

A) 81.6°
B) 83.2°
C) 83.8°
D) 80.6°
E) 79.6°