Identify the true statements regarding α‑1,6 linkages in glycogen.

(a) branching increases glycogen solubility.
(b) new α‑1,6 linkages can only form if the branch has a free reducing end.
(c) the number of sites for enzyme action on a glycogen molecule is increased through α‑1,6 linkages.
(d) exactly seven residues extend from these linkages.
(e) the reaction that forms α‑1,6 linkages is catalyzed by a branching enzym