​CORRECT OPTION?

​CORRECT OPTION? Question 21 of 90 For any reaction. Rate low obtained is :rate = k [A1 [B] Select the correct option 2. 4. O O o Reaction must be elementary Reaction must be complex Reaction may be elementary or complex None of these

Dear Student,

For elementary reactions, order of reaction is same as molecularity and order with respect to each reactant is equal to its stoicheometric coefficient in the balanced chemical equation of reaction. 

Here, Molecularity and order cannot be determined as the reaction is not balanced. 
Hence, the correct answer is (3)