Explanations:The climate of a region is influenced by several factors, including its geographical location, altitude, and proximity to water bodies. Coastal cities, such as Mumbai and Kolkata, experience a moderate climate due to the moderating effect of the sea. The sea breeze helps to regulate temperature extremes, making the climate more temperate. This is why Mumbai and Kolkata are known for their moderate climate, which is neither too hot nor too cold throughout the year.
On the other hand, Patna and Lucknow, located in the northern plains of India, experience a more extreme climate. The northern plains are characterized by hot summers and cold winters, with significant temperature variations between the seasons. This climate is not considered moderate, as the temperature extremes are more pronounced compared to coastal regions.
Bikaner and Jaisalmer, located in the desert region of Rajasthan, experience a harsh, arid climate with extreme temperature variations. The desert climate is characterized by very hot days and cold nights, with little to no rainfall. This climate is far from moderate and is known for its extreme conditions.
Ranchi and Asansol, located in the eastern part of India, experience a humid subtropical climate. This climate is characterized by distinct wet and dry seasons, with high humidity levels and significant rainfall during the monsoon season. While the climate can be comfortable during certain times of the year, it is not considered moderate due to the high humidity and the distinct wet and dry seasons.
Therefore, the correct answer is Option A, as Mumbai and Kolkata are coastal cities that experience a moderate climate due to the moderating effect of the sea. This climate is more temperate and less extreme compared to the other options provided.