Explanation:

In the Tibetian Himalaya, Namcha Barwa is a mountain peak. On reaching the Namcha Barwa, the Tsangpo -Brahmaputra River takes a U turn and enters India through a gorge in Arunachal Pradesh. Hence, this option is correct.

statement 2 is correct and complete explanation of Middle Himalayas is as given below.

Middle Himalayas or Lesser Himalayas

• In between the Shiwaliks in the south and the Greater Himalayas in the north.
• Runs almost parallel to both the ranges.
• It is also called the Himachal or Lower Himalaya.
• Lower Himalayan ranges are 60-80 km wide and about 2400 km in length.
• Elevations vary from 3,500 to 4,500 m above sea level.
• Many peaks are more than 5,050 m above sea level and are snow covered throughout the year.
• Lower Himalayas have steep, bare southern slopes [steep slopes prevents soil formation] and more gentle, forest covered northern slopes.
• In Uttarakhand, the Middle Himalayas are marked by the Mussoorie and the Nag Tibba ranges.
• The Mahabharat Lekh, in southern Nepal is a continuation of the Mussoorie Range
• East of the Kosi River, the Sapt Kosi, Sikkim, Bhutan, Miri, Abor and Mishmi hills represent the lower Himalayas.
• The Middle Himalayan ranges are more friendly to human contact.
• Majority of the Himalayan hill resorts like Shimla, Mussoorie, Ranikhet, Nainital, Almora and Darjeeling, etc. are located here.