please help me answer these questions with explanation

Chapter 19 (Reaction of Benzene) Study guide 1) Provide a detailed, stepwise mechanism for the following reaction. +OCH3 2) Which of the following is most reactive toward nucleophilic aromatic substitution I. IV. II. III. V. A) I B) II C) III D) IV E) V 3) What reagent is used to convert an arenediazonium salt into a fluoroarene? A) HBF4 B) F2 C) HF D) BF3 E) B2F6