Presence of aldehyde group in glucose is indicated by its reaction withA) Br2/H2OB) Tollen's reagentC) Fehling's reagentD) conc.HNO3

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-CHO to  -COOH group but oxidizes primary alcohol group-CH2OH also to -COOH  group;It is thus useful to detect the presence of primary alcohol groupCH2OH in glucose ;