9. (15 points) There are two functions / and g. The graphs of their derivatives are given below. For each given statement: Write TRUE if the statement MUST be true. Write FALSE if the statement MUST be false. Write NED if there is not enough information to decide. (i.c. if the statement might be true and might be false.) B'( x) f'(x) 1-2- -4- -6- - 8- -10 - (a) g"(r) is a decreasing function. (b) /(r) is a decreasing function. (c) g(r) is always concave down. (d) /(x) has no local minimum. (e) /(x) is never zero