Explanation:

The correct answer is option 3: Maintaining sacred groves.

Biodiversity refers to the variety of living organisms in an ecosystem. It is an essential aspect of maintaining the balance and stability of ecosystems. Several factors can contribute to a decrease in biodiversity, but sacred groves are actually known for their role in preserving biodiversity.

Option 1: Large scale deforestation refers to the cutting down of forests on a massive scale. This can lead to a significant loss of habitat for many species and result in a decrease in biodiversity.

Option 2: Exploitation of forest produce involves the excessive harvesting of resources from forests, such as timber or plants. This can disrupt the natural balance of the ecosystem and contribute to the decline of certain species.

Option 4: Encroachment in forest areas refers to human activities such as settlement, agriculture, or infrastructure development in forested regions. This can lead to habitat destruction, fragmentation, and displacement of wildlife, ultimately resulting in a loss of biodiversity.

In summary, maintaining sacred groves actually helps to preserve biodiversity, making option 3 the correct answer.