It is important to know the vertex form of a quadratic equation to answer this question. The form is y=a(x-h)^2 +k. In this equation, the variable h corresponds to the x-coordinate of the vertex of the graph and k corresponds to the y-coordinate of the vertex of the graph. So, in this case, the vertex falls at the point (0.25 , 6), which we can see by looking at the given graph. Knowing this, we can immediately see that answer choice D shows 0.25 as the h value and 6 as the k value, which are the exact coordinates of the vertex. D is the correct answer.