The function $f$ has the property that $f(x)$, $f'(x)$, and $f''(x)$ are negative for all real values $x$. Which of the following could be the graph of $f$ ?

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If $f(x)$ is negative, all points on the graph should have negative $y$-values (Quadrant III and IV only).

If $f'(x)$ is negative, the graph should be decreasing at all intervals.

If $f''(x)$ is negative, the graph should be concave down. The slope should be becoming more negative as $x$ increases.