Consider the function f from set A={1,2,3,4} into set B = {Q,B} given by f(1) = a f(2)= a f(3) =B f(4)=B A. The inverse -1:B+ A given by f-1 = {(a,1),(a,2),(3,3),(3,4)} which is a binary relation but not a function. B. Fully defined and injective, but not surjective. C. The inverse f-1:B+ A given by f-1 = {(a,1),(0,2),(3,3), (8,4)} which is a fully-defined function. D. Fully defined and surjective, but not injective