The following sentence has been split into some parts. Identify the part that contains a grammatical error. If you don't find any error, mark 'No error' as your answer.
Charith speaks so polite / with his neighbours / but they are always very rude to him.

Correct option is B

Option (b) contains the grammatical error. The error in the part "Charith speaks so polite" is due to the use of the adjective "polite" instead of the adverb "politely."
The verb "speaks" should be modified by an adverb, so the correct phrase should be "Charith speaks so politely."
· Grammatical rule used: Adverbs modify verbs, adjectives, or other adverbs, providing information about how, in what manner, when, or where something happens. In this case, "politely" is the adverb modifying the verb "speaks."
· Example: He always speaks quietly during meetings.