(1 point) Suppose that 10) = 3ex + 6' (A) Find all critical points of f. If there are no critical points, enter None. If there are more than one, enter them separated by commas, e.g. 0,1 Critical point(s) at r = (B) Use interval notation to indicate the interval(s) where f(a) is concave up. (Use commas T to separate multiple intervals.) Concave up: (C) Use interval notation to indicate the interval(s) where f() is concave down. (Use commas ". to separate multiple intervals.) Concave down (D) Find all inflection points of f. If there are no inflection points, enter None, If there are more than one, enter them separated by commas. Inflection point(s) at a =