A.∑m(1,2,4,7),∑m(3,5,6,7)
B.∑m(1,2,4,7),∑m(1,3,6,7)
C.∑m(1,2,4,7),∑m(4,5,6,7)
D.∑m(1,2,3,7),∑m(3,5,6,7)