The gradient of x axis is zero. As such, the gradient of the line parallel to x-axis can only be zero
right 3 units down 5 units

right 3 units = (3,0)
down 5 units = (0,-5)
vertex = (h,k) therefore.

Then convert the vertex form into standard form for the equation in the choice.

Thus, the answer is B.
For the function

We can use the formula for the axis of symetry, which is

With the values substituted, we get...

Therefore the axis of symmetry is
Da answer is cCbecause it is