The correct option is C 1113
2a+3b+4c=11
Possible combination of (a,b,c)
(0,1,2),(1,3,0),(2,1,1),(4,1,0)
Hence, the coefficient of x11 in (1+x2)4(1+x3)7(1+x4)12 is :
( 4C0× 7C1× 12C2)+( 4C1× 7C3× 12C0)+( 4C2× 7C1× 12C1)+( 4C4× 7C1× 12C0)=462+140+504+7=1113