The correct order for the rate of $\alpha,\beta$-dehydrohalogenation for the following compounds is ____. (i) 1-iodopentane; (ii) 2-iodopentane; (iii) 2-iodo-2-methylbutane (tertiary halide) [add image]
A (i) < (ii) < (iii)
B (ii) < (i) < (iii)
C (iii) < (ii) < (i)
D (ii) < (iii) < (i)