Explanation:

Correct Answer : (3) 
According to the news published in the Hindu, Solar Hamam, a locally made and well known heating system, is gaining popularity in Himachal Pradesh, Ladakh, and Uttarakhand.

Solar Hamani aims to provide clean energy solutions for homes in mountainous regions. It seeks to save forests, free women from firewood, and reduce carbon emissions.

Solar Hamam offers a place to keep out the cold. It provides 15 - 18 liters of hot boiling water, within the first sunlight for 30-35 minutes, at a maximum temperature of 90 ° C in the morning. Consecutive botches of hot water are available for 15 20 minutes apart.