Assertion $(A) :$ Sucrose is a disaccharide and a non-reducing sugar.

Reason $(R) :$ Sucrose involves glycosidic linkage between $C_{1}$ of $\beta$-glucose and $C_{2}$ of $\alpha$-fructose.

Choose the most appropriate answer from the options given below :

Statments $I:$ Maltose has two $\alpha$-D-glucose units linked at $C _{1}$ and $C _{4}$ and is a reducing sugar.

Statement $II:$ Maltose has two monosaccharides: $\alpha$-D-glucose and $\beta$-D-glucose linked at $C_{1}$ and $C_{6}$ and it is a non-reducing sugar.

In the light of the above statements, choose the correct answer from the options given below.