#### Answer

C

#### Work Step by Step

According to the text, the graph of the function $y=c+f(x)$ is translated vertically compared to the graph of $y=f(x)$. If $c$ is greater than zero, the translation is $c$ units up and if $c$ is less than zero, the translation is $|c|$ units down.
We now compare the equation $y=-1+\cos x$ to $y=c+f(x)$. Upon inspection, we find that $c=-1$. Since $c$ is negative, the graph of $y=-1+\cos x$ will be the same as the graph of $y=\cos x$ except that it will be translated $1$ unit down.
Therefore, we need to find a graph which is the same as the graph of $y=\cos x$ except that it is translated $1$ unit down. Such a graph is found in option C.