Lactose is a sugar molecule made up of two subunits: D-glucopyranose and D-galactopyranose. These subunits are connected by a β-1,4′-glycosidic linkage. In an experiment, lactose was treated with two chemical processes: first with methyl iodide (CH₃I) in excess with silver oxide (Ag₂O), then with HCl/H₂O. After these treatments, it was observed that the D-galactopyranose part had only one hydroxyl (OH) group that wasn't converted to a methoxy group, while the D-glucopyranose part had two such groups. Draw the structure of α-lactose based on this information.