To the ordinary man, in fact, the pealing of bells (1)/ is a monotonous jangle and a nuisance (2) / tolerably only when mitigated by remote distance and sentimental association. (3) / No error. (4)

Answer

3

Explanation

tolerable will replace tolerably because
- an Adj. qualifies a Noun and tolerable is an Adj. and tolerably is an Adv. peal (Noun): a loud sound or series of sounds
monotonous (Adj.): never changing and therefore boring
jangle (Noun) : a hard noise like that of a metal hit ting metal.
mitigated (Verb): to make something less harmful, serious, etc.
Hence, tolerable only when mitigated by remote distance and sentimental association is the right usage.