"Rahul, whydoyou not pay head to my words,"said Laxmi​

The given sentence is a statement.

According to the rules of narration and reporting, if the reporting verb is in the past tense, the tense of the reported verb is changed into its corresponding past form. The reporting verb in the given sentence, 'said', is in the past form. Therefore, the reported verb, 'cannot' will change into 'could not'. The first person pronoun 'I' will change to third person 'he'.

Thus, in indirect speech the sentence must be,

He said that he could not help me at present because he was himself in difficulty.

Thus option B is the correct answer.

Options A,B,D are incorrect as they do not follow the rules of Narration and Reporting.