Arrange the following alkyl chlorides in order of decreasing reactivity in an `S_(N^(1)` reaction : (I) isopropyl bromide , (II) propyl bromide
(III) tert-butyl bromide , (IV) methyl bromide
A. `(III)gt(I)gt(II)gt(IV)`
B. `(I)gt(III)gt(IV)gt(II)`
C. `(IV)gt(III)gt(II)gt(I)`
D. `(I)gt(II)gt(III)gt(IV)`
