Which of the following is a monosaccharide?

Which of the following carbohydrates has the $L$-configuration?

$A$ polysaccharide '$X$' on boiling with dil $H_2SO_4$ at $393 \ K$ under $2-3 \ atm$ pressure yields '$Y$'. '$Y$' on treatment with bromine water gives gluconic acid. '$X$' contains $\beta-$glycosidic linkages only. Compound '$X$' is ..... .

What is the quantity of water required to obtain one mole of glucose from one mole of sucrose by acid hydrolysis (in $g$)?

Name the sugar present in milk. How many monosaccharide units are present in it? What are such oligosaccharides called?

Which one of the commercial products is used to grow microbes and in the preparation of ice-creams and jellies?