Find the Open Intervals on Which the Function $y = \left\{ \begin{array} { l } 2 x + 7 , x \leq 7 \\4 - x ^ { 2 } , x > 7\end{array} \right.$

Multiple Choice

Find the open intervals on which the function $y = \left\{ \begin{array} { l } 2 x + 7 , x \leq 7 \\4 - x ^ { 2 } , x > 7\end{array} \right.$ is increasing or decreasing.

A) The function is increasing on the interval $- \infty < x < 0$ and decreasing on the interval $0 < x < \infty$ .
B) The function is increasing on the interval $7 < x < \infty$ and decreasing on the interval $- \infty < x < 7$ .
C) The function is increasing on the interval $- \infty < x \leq 7$ and decreasing on the interval $7 < x < \infty$ .
D) The function is increasing on the interval $0 < x < \infty$ and decreasing on the interval $- \infty < x < 0$ .
E) The function is increasing on the interval $- \infty < x < 7$ and decreasing on the interval $7 < x < \infty$ .