Which of the following reagents cannot distinguish between glucose and fructose ?

The reason is that in the basic or acidic medium fructose will rearange to aldose and give the test, The detail reason is as 

Lobry De Braun–Alberda van Elkenstein re-arrangement reaction is the base or acid catalyzed re-arrangement of an aldose into the ketose isomer, into a mixture of monosaccharides. The intermediate is a tautomeric ene-diol. Which is the main reason for isomerization.