(i) The group activates benzene ring more by resonance effect.
group being more electronegative hence it withdraws electrons from benzene ring and shows effect.
(ii) The methyl group of ether can donate electrons through inductive effect that is not as strong as electron donation effect ot the pi-system. Thus, resonance effect dominates over inductive effect in anisole.

(iii) -nitorbenzoic acid is more acidic than m-nitrobenzoic aci. when both acids donate form group, then -nitrobenzoate is more stabilised due to effect of nitro group meta -position is not much pronounced henic. statement (iii) is incorrect.
(iv) Diphenylamine is less basic than aniline. The lone pair of electron on the -atom in diphenylamine is delocalised on two benzene rings due to which it is less available to donate resulting into decrease in basicity. In aniline, it is delocalised on one benzene ring, so lone pair is more available for donation. Hence, it is more basic.