Presence of aldehyde group in glucose is indicated by its reaction with

A) ${\mathrm{Br}}_2/{\mathrm{H}}_2\mathrm{O}$

B) $\mathrm{Tollen}\text{'}\mathrm{s} \mathrm{reagent}$

C) $\mathrm{Fehling}\text{'}\mathrm{s} \mathrm{reagent}$

D) $\mathrm{conc}.{\mathrm{HNO}}_3$

Aldehyde group is very much susceptible to oxidation;

A,B,C are mild oxidizing agents;

They oxidize glucose to gluconic acid;

They cannot oxidize primary alcohol group;

Concentrated nitric acid not only oxidizes aldehyde group$\left(-\mathrm{CHO}\right)$ to  $-\mathrm{COOH}$ group but oxidizes primary alcohol group$\left(-{\mathrm{CH}}_2\mathrm{OH}\right)$ also to $-\mathrm{COOH}$  group;

It is thus useful to detect the presence of primary alcohol group$\left({\mathrm{CH}}_2\mathrm{OH}\right)$ in glucose ;