Explanation:

Correct Option: (c) Explanation:  Statement 1 is incorrect: A jet stream is a river-like current of air circulating across the globe at upper levels of the troposphere (near the altitude of 30,000 feet) whereas a western disturbance (WD) is an extratropical storm which originates in the Mediterranean region. Supplementary notes: Western Disturbance  According to the India Meteorological Department (IMD), a western disturbance is likely to affect the Himalayan region soon.  The disturbances will result in fairly widespread light to moderate snowfall and rains in the plains of Jammu.  A western disturbance (WD) is an extratropical storm which originates in the Mediterranean region.  The disturbance travels from the “western” to the eastern direction. Disturbance means an area of “disturbed” or reduced air pressure. Equilibrium exists in nature due to which the air in a region tries to normalise its pressure.  In the term “extra-tropical storm”, storm refers to low pressure. “Extra-tropical” means outside the tropics. As the WD originates outside the tropical region, the word “extra-tropical” has been associated with them.  A WD is associated with rainfall, snowfall and fog in northern India. Upon its arrival in Pakistan and northern India, clouds along with rain and snow also arrive. The moisture which WDs carry with them comes from the Mediterranean Sea and/or from the Atlantic Ocean.  WD brings winter and pre-monsoon rain and is important for the development of the Rabi crop in the Northern subcontinent.  The WDs are not always the harbingers of good weather. Sometimes WDs can cause extreme weather events like fl oods, fl ash fl oods, landslides, dust storms, hail storms and cold waves killing people, destroying infrastructure and impacting livelihoods.