Final answer:
The axis of symmetry for a quadratic equation f(x) = ax^2 + bx + c is x = -b/2a, which is a vertical line that bisects the parabola and corresponds to the x-coordinate of its vertex.
Step-by-step explanation:
The axis of symmetry for a quadratic equation of the form f(x) = ax^2 + bx + c, is given by the formula x = -b/2a. This axis of symmetry is a vertical line that divides the parabola into two mirror images. It also corresponds to the x-coordinate of the vertex of the parabola. The correct answer to the student's question is A) x = -b/2a.