4x + 81x + 401 2x - 34 f(x) = f" (x)= X + 20x + 100 (x + 10)" Determine the concavity of f. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. O A. The curve is concave down on ( - co,17) and concave up on (17,co) (Type your answers in interval notation.) O B. The curve is concave down for all real numbers. O C. The curve is concave up for all real numbers. X U L,I e 4