Please answer this question

Definition: The AREA A of the region S that lies under the graph of the continuous function f is the limit of the sum of the areas of approximationg rectangles A = lim Rn = lim [f(x1)Ax + f(22)Ax+. . . +f(X,) Ax] \\vspacelin (a) Use the above definition to determine which of the following expressions represents the area under the graph of f (ae ) = a from ac = 0 to ac = 2. O 64 A. lim 64 B. lim n->00 LM= IM= IM : I'M O C. lim O D. lim N . 2-00 (b) Evaluate the limit that is the correct answer to part (a). You may find the following formula helpful: 15 + 25 + 35 + ... tn' = 5 n' (n + 1)2(2n2 + 2n - 1) 12 Value of limit =