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

Multiple Choice

Find the angle between the two planes in degrees. Round to a tenth of a degree.
$$\begin{array} { l } x + 3 y + 6 z = 4 \\x - 6 y - z = 4\end{array}$$

A) $9.4 ^ { \circ }$
B) $33.4 ^ { \circ }$
C) $123.4 ^ { \circ }$
D) $28.8 ^ { \circ }$
E) $2.2 ^ { \circ }$