The question is incomplete as the chemical structures of the compounds are missing from the input data, making it impossible to independently determine the conceptually correct order. However, the rate of $\alpha,\beta$-dehydrohalogenation (an elimination reaction) generally depends on the nature of the alkyl halide and the stability of the product alkene. For a given halogen, the rate of dehydrohalogenation follows the order: tertiary > secondary > primary . Based on the provided probable answer, the order is (ii) < (iii) < (i).