Hi there! The answer is A.
[tex]f(x) = - 2 {x}^{2} [/tex]
In the graph we can see is a parabola (so B. cannot be the answer) with a vertex at the point (0, 0), which means the parabola is not translated upwards or downwards. Therefore, only A. can be correct, since all the other formulas include a translation downwards (which can be deduced from the -2 in the formula).