The Himalayan Pass that was reopened around the middle of the year 2006 to facilitate trade between India and China is Nathu La (Option 3). Nathu La Pass is a mountain pass located in the eastern section of the Himalayas, connecting the Indian state of Sikkim with the Tibet Autonomous Region of China.

Here`s the detailed reasoning:

1. Historical Importance:

Nathu La Pass has a significant historical importance in the context of trade between India and China. It served as a crucial route for trade and cultural exchanges between the two countries for centuries. However, it was closed in 1962 due to the Sino-Indian War and remained closed for over four decades.

2. Reopening in 2006:

The reopening of Nathu La Pass in 2006 was the result of diplomatic negotiations between India and China. The agreement to reopen the pass was signed during the visit of the Chinese Premier Wen Jiabao to India in April 2005. This decision was aimed at reviving the traditional trade route and promoting bilateral trade and tourism between the two nations.

3. Trade Facilitation:

The reopening of Nathu La Pass has significantly facilitated trade between India and China. It has provided a shorter and more direct route for the movement of goods and services, reducing the distance and time required for trade. This has boosted economic ties and bilateral trade between the two countries.

4. Infrastructure Development:

To facilitate trade through Nathu La Pass, both India and China invested in infrastructure development in the region. The Indian government constructed a new road, improved border facilities, and established trade-related infrastructure like warehouses and customs checkpoints. China also made substantial investments in upgrading their side of the infrastructure.

5. Cultural Exchange and Tourism:

Apart from trade, the reopening of Nathu La Pass has also promoted cultural exchanges and tourism between India and China. It has allowed people from both nations to travel more easily and experience the diverse cultures and traditions of the region. This has fostered greater understanding and friendship between the two countries.

It is important to note that while Chang La (Option 1), Jara La (Option 2), and Shipki La (Option 4) are also mountain passes located in the Himalayas, they do not specifically pertain to the reopening of trade between India and China in 2006. Nathu La Pass is the correct option in this context based on the historical significance, reopening in 2006, and the subsequent trade and cultural exchanges between India and China.