Answer:
The answer A) n=5
Step-by-step explanation:
Find the least common multiple.
The left denominator is "N"
The right denominator is "5"
That's how you get the answer N=5
In any parabola, the vertex is the turning point. And the x-coordinate of the vertex can be found using

So, in your case, you have

So, your equation actually looks like

Now impose the passing through (2,1), i.e. substitute x=2, y=1 and solve for b:

The answer will be the set of points that contains a different x value for each point.
We clearly see that for ever point in terms of CHOICE C the value of x is different.
Answer: Choice C