I'm confused, can someone explain? ?

answer choices:

a) y = 10x
b) x = 10
c) x = y + 10
d) y = x + 10

Option B x =10

Step-by-step explanation:

The axis of symmetry of a parabola divides it into two similar parts. In this type of parabola the axis of symmetry always passes through its vertex.

In this case the vertex is to the point where the function is maximum. Note that the function is maximum at the point x = 10 and y ≈ 800

Then the axis of symmetry is perpendicular to the x axis and passes through the point (10,800)

Therefore the axis is the line x = 10

Option B

astronomers is your final answer! : )