The standard form of a parabola is

, where h and k are the coordinates of the vertex and the a is the value that either compresses it vertically or draws it out horizontally (aka stretched). The h value also indicates side to side movement, while the k value indicates up or down movement. The larger the a value, the closer the parabola "hugs" the axis of symmetry. All in all here, we have a parabola in g(x) that is vertically compressed and is moving down from its original vertex of f(x) which (0, 0) by 2 units. Therefore, our choice is b.