The correct option is B Ann said that she wanted to go to Jaipur the following week
When a sentence is changed from direct to indirect speech, the subject pronoun, verbs and tense forms also change. (This is because the speech is reported by someone else, and the tense of the direct speech goes one tense back as it's spoken at a later time now.) The meaning of the sentence should not be changed.
Option B contains the reported speech as the words are changed according to tense and person, keeping the meaning of the sentence unchanged.
When the direct speech is in present tense (want), the reported speech will change to its corresponding past tense (simple past) 'wanted'. Also, the adverb 'next week' is changed to 'the following week'. Hence B is the correct option.
Option A: The tense of the verb has not been changed here. Only the person is changed from 'I' to 'she'. But it still remains in present simple tense. Hence A is incorrect.
Option C: 'Going' is a present participle whereas the original form of the verb 'to go' is an infinitive. The infinitive won't change, as it doesn't display tense. Hence C is incorrect
Option D is incorrect because the tense of the direct speech has not been changed to past. Also, the reporting verb 'said' and the conjunction 'that' is missing. These are essential while reporting the speech.