Which one of the following compounds contains - C1 - C4 glycosidic linkage?

Step 1: Identifying Glycosidic Linkages — Glycosidic bonds are defined by the carbons they connect and the stereochemistry ($\alpha$ or $\beta$) at the first carbon.

Step 2: Lactose Structure — Lactose is composed of $\beta\text{-D-galactose}$ and $\text{D-glucose}$ joined by a bond between $\text{C1}$ of galactose and $\text{C4}$ of glucose.

Step 3: Result — This specific connection is a $\beta\text{-C1-C4}$ linkage. In contrast, maltose uses an $\alpha\text{-1,4}$ linkage.

Key Point: The $\beta$-linkage in lactose requires the enzyme lactase for human digestion.