With reference to the palaeolithic period of India, consider the following statements.

1. The Palaeolithic period is characterised with the Holocene period, chopper-chopping stone tools, hunting-gathering society.

2. The people lived in small groups in open air sites or in caves for long periods of time.

3. From the lower to upper palaeolithic period, there was a gradual increase in size of tools and improvement of tool technology.

4. Soan and Acheulian were two important tool cultures in the middle palaeolithic period.

Which of the above statements is/are not correct?