## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$d$
The general equation for a parabola that has the axis of symmetry parallel to the $y$-axis and opens up is given by: $(x−h)^2=4a(y−k)$ Where, $(h, k)$ is the vertex of the parabola. We are given that the coordinates for the vertex are $(3,2)$ and the focus is $f=4$ units with coordinates: $(3, 2+f) \to (3,6)$ Therefore, the required option is $(d)$.