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Explanation:

Step1: Recall cosine - function properties

The general form of a cosine function is $y = A\cos(Bx - C)+D$. For the function $y=-3\cos(3x)$, we have $A=-3$, $B = 3$, $C = 0$, and $D = 0$.

Step2: Determine the amplitude

The amplitude of the function $y = A\cos(Bx)$ is given by $|A|$. Here, $|A|=| - 3|=3$, so the maximum value of the function is $3$ and the minimum value is $-3$.

Step3: Determine the period

The period of the cosine function $y=\cos(Bx)$ is $T=\frac{2\pi}{|B|}$. For $y=-3\cos(3x)$, $B = 3$, so the period $T=\frac{2\pi}{3}$.

The cosine - function $y = \cos(x)$ has a maximum at $x = 0$. The function $y=-3\cos(3x)$ has a minimum at $x = 0$ (because of the negative sign in front of the cosine function). The graph that has a minimum at $x = 0$, an amplitude of $3$, and a period of $\frac{2\pi}{3}$ is the correct one.

Answer:

The graph that has a minimum value of $- 3$ at $x = 0$ and a period of $\frac{2\pi}{3}$ (the graph with more frequent oscillations compared to the standard cosine - graph and inverted with respect to the $x$ - axis). Without specific labels for the graphs, it's the graph that starts at $y=-3$ when $x = 0$ and has a relatively short - wavelength (high frequency) compared to the standard cosine function $y=\cos(x)$.