Solve the equation for y

Answer this question only if you know the answer! 30 points and

On a piece of paper graph f(x)=5•(0.4)^x

Which of the following equations is of the parabola whose vertex is at (4, 3), axis of symmetry parallel to the y-axis and focus at (4, -3)? a.) y+3=1/24 (x+4)^2 b.)y-3=-1/24 (x-4)^2 c.)x-4=-1/24 (y-3)^2