The following sentence has been divided into four segments. Identify the segment that contains a grammatical error.
She was singing / beautifully in / the concert hall / last night.

Correct option is C

Correct Sentence: She was singing beautifully at the concert hall last night.
Explanation:
The error lies in the incorrect use of the preposition "in". For performances or events at specific venues like halls, theatres, etc., the correct preposition is “at.”
Grammar Rule – Prepositions of Place:
· Use "at" to refer to a point or specific location.
· Example: She performed at the Royal Opera House.
Analysis of Options:
· (a) She was singing – grammatically correct (past continuous tense).
· (b) the concert hall – noun phrase, correct.
· (c) beautifully in – error; should be beautifully at.
· (d) last night – correct adverb of time.