Which of the following is not a mineral acid?

Explanation:
Mineral acid is derived from inorganic substances and dissolved in water to form ions.

HCl                +             H2O            H3O+     +                 Cl-
                            (Hydrochloric acid)        (Water)          (Hydronium ion)       (Chloride ion)

                                                                                    

        H2SO4                +             H2O            H3O+     +                 HSO4-
                            (Sulphuric acid)               (Water)          (Hydronium ion)       (Hydrogen sulfate)




        HNO3                +             H2O            H3O+     +                 NO3-
                             (Nitric acid)                      (Water)          (Hydronium ion)       (Nitrate)

Citric acid is an organic acid that doesn’t dissociate in water.

Final Answer:
Hence, Option (B) is correct.