Explanation:

- 1 February: Since 2017, the Union Budget of India has been presented on 1 February. This change was made from the earlier practice of presenting it on the last working day of February.

- Correct Answer: 1 February

- 1 August: This date has no significance in terms of the Union Budget. August usually falls in the middle of the financial year, making it an unlikely time for budget presentation.

- 1 January: There is no historical precedent or policy for presenting the Union Budget on this date.

- 1 October: This also is not a date associated with the Union Budget delivery, as it is midway through the fiscal year.

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