Answer
$\text{(I)}$
Work Step by Step
The amplitude and period can be calculated as, if $y=A\cos(wx)$:
Amplitude=$|A|$,
period: $T=\frac{2\pi}{w}$
In this function, $y=3\cos(2x)$
Amplitude=$3$
Period: $T=\frac{2\pi}{2}=\pi$
Also, the cosine function does not have a y-intercept at the origin, rather at $y=3$.
The graph that has the same characteristics is $\text{(I)}$.