Of the following statements , which are true for `S_(N)2` reaction.
(a) Tertiar alkyl halides reacts faster than secondary.
(b) The absolute configuration of product is opposite to that of the reactant when an optically active substrate is used.
(c) The used shows first order kinetics.
(d) The rate of the reaction depends markedly on the nucleophilicity of the attacking reagent.
(e) The mechanism is one step.
(f) Carbocations are intermediate.
(g) Rate `prop` [Alkyl][halides]
(h) The rate of the reaction depends on the nature of the leaving group.
