Looks like all real numbers except 1. It touch's all the y except 1 aka range
I think the correct answer is C. Since a=πr², in order to get the area to become 1/4 of what it was previously, the radius needs to be cut in half to make the divide that side by 4. a=π(r/2)²=πr²/4 and will therefore multiply the area by 1/4.
I am assuming that you mean

and

Now, let's look for common factors. The first one is

After we take that out, we are left with 14 and 22. We can take a 2 out of both of these, so the greatest common factors is