Which of the following statements about nucleophilic aromatic substitution is true? multiple choice a. in the addition-elimination mechanism, the aromatic ring first accepts a pair of electrons from a nucleophile to form a cationic intermediate. b. for the elimination-addition pathway, the nucleophile becomes attached only at the site bearing the leaving group. c. for the addition-elimination pathway, the nucleophile may become attached either at the site bearing the leaving group or at the site bearing the ortho hydrogen atom. d. the elimination-addition mechanism is not as common as the addition-elimination mechanism.