The correct answer is: a) Neolithic agricultural developments.
Shifting cultivation, also known as slash-and-burn agriculture, is a traditional agricultural system in which the natural vegetation is cleared and burned, and the ashes are used to fertilize the soil. The land is then cultivated for a few years, until the soil becomes depleted, and then the farmers move on to a new area.
Shifting cultivation is a sustainable agricultural practice when it is practiced in a way that allows the land to recover between cultivation cycles. However, when it is practiced too frequently, it can lead to deforestation and soil erosion.
The practice of shifting cultivation is thought to have originated in the Neolithic period, when humans first began to practice agriculture. It is still practiced today in many parts of the world, including in Sikkim.
The other options are incorrect because:
- Option b) is incorrect because influence from neighboring regions is not the primary reason for the practice of shifting cultivation in Sikkim.
- Option c) is incorrect because modern agricultural techniques are not typically used in shifting cultivation.
- Option d) is incorrect because the British colonial period did not have a significant impact on the practice of shifting cultivation in Sikkim.