Which of the following is a reducing sugar?

The Fischer projection formula of $D-(-)$-fructose is:

The formation of a silver mirror by $Glucose$ indicates that it acts as a/an:

Glucose + ? $\longrightarrow$ Sucrose

Which of the following molecules serves as fibrous content of food only and is useful for bowel movement in humans?

Two statements are given below.
Statement $I$: Milk sugar is a disaccharide of $\alpha-D$-galactose and $\beta-D$-glucose.
Statement $II$: Sucrose is a disaccharide of $\alpha-D$-glucose and $\beta-D$-fructose.
Correct answer is