The correct option is D in
Phrasal verbs are phrases, formed with a verb and a preposition or an adverb. The meaning thus formed is different from its literal meaning.
Option D: 'Gave in' is a phrasal verb that means 'to finally agree to what someone wants'. The meaning relates to the sentence, as Rachna finally agreed to 'everyone's request' and sang. Hence option D is correct.
Option A: 'Gave on' means 'to attack'.
Option B: 'Gave off' means 'to produce something such as heat, light or a smell'.
Option C: 'Gave up' means 'to stop doing or believing in something'.
These meanings do not relate to the given sentence. As a result, each sentence that is formed is vague in meaning.
Hence options A, B and C are incorrect.