Boojho , Paheli and their firend Golu were provided with a test tube each containing China rose solution which was pink in colour .Boojho added two drops of solution 'A' in his test tube and got dark pink colour .Paheli added 2 drops of solution 'B' to her test tube and got green colour.Golu added 2 drops of solution 'C' but could not get any change in colour Suggest the possible cause for the variation in their results.