Explanation:

- Option 1: 14 July 1942

This date does not hold any significance in relation to the 'Do or Die' speech.

- Option 2: 23 March 1942

This date is not related to the speech. In March 1942, the Cripps Mission arrived in India.

- Option 3: 24 September 1942

Nothing noteworthy regarding Gandhiji or the speech happened on this date.

- Option 4: 8 August 1942

This is the correct date when Mahatma Gandhi delivered the 'Do or Die' speech. It was at the All-India Congress Committee session in Bombay, marking the start of the Quit India Movement.