Volume of the pyramid = (1/3) x Area of the base x Height ---------- (1)
As the base length = 5 feet
So Area of the base = 5 x 5 = 25 square feet
While volume of the pyramid = 75 cubic feet
Putting values in equation (1);
75 = (1/3) x 25 x Height
Height = (75 x 3) / 25
Height = 9feet
So 2nd option is correct.