Option 1: If the Himalayas did not exist, it is unlikely that monsoon rains would have taken place in the winter months. The Himalayas play a crucial role in influencing the monsoon winds and causing rainfall in the Indian subcontinent. Without the Himalayas, the monsoon pattern would have been significantly different.

Option 2: If the Himalayas did not exist, it is unlikely that coastal India would have experienced a Mediterranean climate. The presence of the Himalayas affects the air circulation patterns and influences the climate of the region. Without the Himalayas, the climatic conditions along the coast would be different.

Option 3: If the Himalayas did not exist, it is likely that the North Indian plain would have been much cooler in winter. The Himalayas act as a barrier, preventing cold winds from entering the plains and creating a buffer against extreme cold temperatures.

Option 4: If the Himalayas did not exist, it is unlikely that the northwestern part of India would have experienced humid conditions. The presence of the Himalayas plays a role in influencing the distribution of moisture and rainfall patterns in different regions.

Therefore, option 3 is correct. If the Himalayas did not exist, the North Indian plain would have been much cooler in winter. Alert