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

Which of the following monosaccharides is a pentose?

Which of the following reagents converts the $-CHO$ and $-CH_2OH$ groups of glucose to $-COOH$ groups?

What is the function of glucose?

Which of the following statements are true about carbohydrates?
$(i)$ Monosaccharides can be hydrolysed.
$(ii)$ The two monosaccharide units obtained on hydrolysis of a disaccharide can either be same or different.
$(iii)$ Polysaccharides are non-sweet in taste.
$(iv)$ All monosaccharides are not reducing sugars.

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Ketoses give Seliwanoff's test faster than Aldoses.
Reason $(R)$: Ketoses undergo $\beta$-elimination followed by formation of furfural.
In the light of the above statements,choose the correct answer from the options given below: