Which points are the vertices of the ellipse?
a) points n and p
b) points o and p
c) points q and r
d) points s and t

 1. The general equation of an ellipse is shown below:

 ((x-h)²/a²)+((y-k)²/b²)=1

 2. As you can see in the graph, the center of the ellipse is (0,0),; Then, you have that the formula is:

 ((x-0)²/a²)+((y-0)²/b²)=1
 (x²/a)+(y²/b)=1

 3. The figure attached in the problem shows that the ellipse is vertical, then its vertices are the following points:

 S(0,6) and T(0,-6)

 4. Therefore the correct answer is the las option: d) Points S and T. 

B, 0.4 repeats so it is rational and square root of 16 is 4 so that is rational as well.