$\alpha$-maltose consists of...
One $\alpha$-D-glucopyranose unit and one $\beta$-D-glucopyranose unit with a 1-2 glycosidic linkage
Two $\alpha$-D-glucopyranose units with a 1-2 glycosidic linkage
Two $\beta$-D-glucopyranose units with a 1-4 glycosidic linkage
Two $\alpha$-D-glucopyranose units with a 1-4 glycosidic linkage
