For a parabola, the axis of symmetry divides it into two congruent or identical halves. It passes through the vertex and is thus equal to the x-coordinate of the vertex. For given quadratic equation with a form y = ax^2 + bx - 1, the vertex (h,k) can be obtained using the formulas: h = -b/2a and k is determined by evaluating y at h. In this case, a = -2, b = 6, thus, h = 1.5, k = 3.5. So, the answer is choice A.
