Which one of the following causes is responsible for rainfall during winters in north-western part of India ?

Rainfall in the north-western part of India during the winter months (December to February) is primarily caused by Western Disturbances. These are extra-tropical cyclones that originate in the Mediterranean region and are brought into the Indian subcontinent by the Sub-tropical Westerly Jet Stream.

• Western Disturbances: They provide highly beneficial precipitation for Rabi crops, particularly wheat, in states like Punjab, Haryana, and Rajasthan.
• Retreating Monsoon: This occurs during October-November and primarily brings rainfall to the south-eastern coast (Tamil Nadu).
• South-West Monsoon: This is the primary rainy season for most of India from June to September.
• Cyclonic depressions: While these can cause rain, the specific winter phenomenon in the north-west is uniquely attributed to the Western Disturbances originating from the Mediterranean.