Realize each of the following functions as a minimum two-level NAND-gate circuit and as a minimum two-level NOR-gate circuit. (a) F(A, B, C, D)=B D^' B^' C D A^' B C A^' B C^' D B^' D^' (b) f(a, b, c, d)=ΠM(0,1,7,9,10,13) ·ΠD(2,6,14,15) (c) f(a, b, c, d)=Σm(0,2,5,10) Σd(3,6,9,13,14,15) (d) F(A, B, C, D, E)=Σm(0,2,4,5,11,14,16,17,18,22,23,25,26,31) Σd(3,19,20,27,28) (e) F(A, B, C, D, E)=ΠM(3,4,8,9,10,11,12,13,14,16,19,22,25,27) ? D(17,18,28,29) (f) f(a, b, c, d)=ΠM(1,3,10,11,13,14,15) ·ΠD(4,6) (