To determine how far the firework will travel before it reaches the ground, we need to solve the quadratic equation given by \( h(x) = -x^2 + 15x \) by setting it equal to zero:
\[ 0 = -x^2 + 15x \]
We can factor the equation:
\[ 0 = x(-x + 15) \]
This gives us two solutions:
- \( x = 0 \)
- \( -x + 15 = 0 \) → \( x = 15 \)
The solutions indicate that the firework reaches the ground (height = 0) at \( x = 0 \) (the starting point) and at \( x = 15 \).
Therefore, the firework will travel a total distance of 15 feet before it reaches the ground.
The correct answer is A. 15 feet.