Answer
Option (c)
Work Step by Step
RECALL:
$y=-f(x)$ is the reflection about the x-axis of the parent function $f(x)$.
A reflection about the x-axis changes the parent function's y-coordinate to its opposite sign. (e.g., if $(1, 2)$ is on the graph of $f(x)$, then $(1, -2)$ is on the graph of $-f(x)$.)
This means that if $(3, 6)$ is on the graph of $y=f(x)$, then $(3, -6)$ is on the graph of $y=-f(x)$.
The answer is Option (c).