Chemical Kinetics: JEE Main 2010 Chemistry question

Consider the reaction : Cl₂(aq) + H₂S(aq) → S(s) + 2H⁺ (aq) + 2Cl^– (aq) The rate equation for this reaction is rate = k [Cl₂] [H₂S] Which of these mechanisms is/are consistent with this rate equation? (A) Cl₂ + H₂S $\to$ H⁺ + Cl^– + Cl⁺ + HS^– (slow) Cl⁺ + HS^– $\to$ H⁺ + Cl^– + S (fast) (B) H₂S $\Leftrightarrow$ H⁺ + HS^– (fast equilibrium) Cl₂ + HS^– $\to$ 2Cl^– + H⁺ + S (slow)