Explanation:

All statements are correct.

• The Himalayas are a major factor in the formation of the monsoon winds in India.

• During the summer months, the landmass over the Indian subcontinent heats up rapidly, leading to the formation of a low-pressure system. 

• The Himalayas, which act as a barrier, prevent the cool, dry air from the north from flowing into the region, resulting in a pressure gradient that draws in warm, moist air from the Indian Ocean.

• The Thar Desert, also known as the Great Indian Desert, is a crucial factor in the formation of monsoon winds in India. 

• It acts as a rain shadow area for the Bay of Bengal branch of the monsoon, meaning that it receives very little rainfall due to the barrier created by the Aravalli Mountain range.

• Thus, the Arabian branch of the monsoon, which moves parallel to the Thar Desert, also leads to very little rainfall in the nearby regions. 

Hence option 4th is correct.