In cyclic structure of cellobiose acetal bond is formed between
A. C-1 of `beta`-D-glucopyranose and C-2 of `beta`-D-galactopyranose
B. C-1 of `beta`-D-glucopyranose and C-4 of `beta`-D-galactopyranose
C. C-1 of `beta`-D-glucopyranose and C-4 of `beta`-D-galactopyranose
D. C-1 of `beta`-D-glucopyanose and C-4 of `beta`-D-galactopyranose