Select the reagent from the list below that could be the basis of a simple chemical test that would distinguish between each of the following:
(a) C6H5CONH2 and C6H5CH2NH2
(b) C6H5CH2NH2 and C6H5NHCH3
(c) C6H5NH2 and cyclohexylamine
1. Cold dilute NaHCO3
2. Cold dilute HCl
3. NaNO2, HCl, 5 C, then 2-naphthol
4. C6H5SO2Cl, OH-, then HCl
5. Cold dilute NaOH