ANSWER
See attachment.
EXPLANATION
The cosine function is symmetric with respect to the y-axis.
If the cosine function has an amplitude of 2 then, its range is
-2≤y≤2
If the period is 2 , then its must complete a full cycle on the interval, [-2,0],[0,2], [2,4], etc.
The graph that has all these features is shown in the attachment.
