Which phenol in each of the following pairs is more acidic? Justify your choice.
(a) 2, 4, 6-Trimethylphenol or 2, 4, 6-trinitrophenol
(b) 2, 6-Dichlorophenol or 3, 5-dichlorophenol
(c) 3-Nitrophenol or 4-nitrophenol
(d) Phenol or 4-cyanophenol
(e) 2, 5-Dinitrophenol or 2, 6-dinitrophenol