Identify the glycosidic linkage present in lactose.

Which $L$-sugar on oxidation gives an optically active dibasic acid?

Sugar $X$:
$A.$ is found in honey.
$B.$ is a keto sugar.
$C.$ exists in $\alpha$ and $\beta$-anomeric forms.
$D.$ is laevorotatory.
$X$ is

What is the total number of $-OH$ groups present in a ribonucleoside?

The pair of compounds in which both the compounds give positive test with Tollen's reagent is

Identify the number of oxygen atoms present in saccharic acid.