8. Choose the double integral that is equivalent to the 4 4 y + 1 x4 + 1 2 integral dx dy. 0. (a) 4 y + 1 dy dx x4 + 1 Va (b) 4 y + 1 dy dx + 1 (c) 4 y + 1 x4 + 1 dy dx 0, (d) .2 4 y + 1 dy dx 0. x4 + 1 (e) .2 4 y + 1 x4 + 1 dy dx