Recall the structure of maltose

Maltose is a disaccharide formed by two glucose units.

Its glycosidic linkage is: $\alpha(1 \to 4)$ meaning the anomeric carbon $C_1$ of one $\alpha$-D-glucose is linked to the $C_4$ of the second glucose unit.

Check Statement I

Statement I says:

• Maltose has two $\alpha$-D-glucose units
• linked at $C_1$ and $C_4$
• and is a reducing sugar

This is correct because:

• Maltose is indeed made of two glucose units with an $\alpha(1\to 4)$ glycosidic bond.
• One anomeric carbon remains free in maltose, so it behaves as a reducing sugar.

Therefore, Statement I is true.

Check Statement II

Statement II says:

• Maltose has $\alpha$-D-glucose and $\beta$-D-glucose
• linked at $C_1$ and $C_6$
• and it is a non-reducing sugar

This is incorrect because:

• Maltose is not a $1\to 6$ linked disaccharide.
• The linkage is $1\to 4$, not $1\to 6$.
• Maltose is reducing, not non-reducing.

Therefore, Statement II is false.

Choose the correct option

Since Statement I is true and Statement II is false, the correct option is: $\boxed{\text{C}}$

Comparison with stored answer

Stored correct answer: $\boxed{\text{C}}$

My derived answer matches the stored answer.