The correct answer is C. Plains.
The plains are the largest physiographic region in India, covering about 43% of the country’s land area. They are located in the northern, central, and eastern parts of India, and are characterized by their flat or gently rolling terrain. The plains are home to most of India’s population, and are the country’s most important agricultural region.
The Shivalik hills are a mountain range located in the northern part of India. They are a sub-range of the Himalayas, and are much smaller than the Himalayas in terms of both height and area. The Shivalik hills are home to a number of important rivers, including the Ganges and the Yamuna.
The sandy area is a physiographic region located in the western part of India. It is a vast expanse of sand dunes, and is home to a number of important cities, including Mumbai and Ahmedabad. The sandy area is a popular tourist destination, and is known for its beautiful beaches.
The Aravali hills are a mountain range located in the northwestern part of India. They are a sub-range of the Himalayas, and are much smaller than the Himalayas in terms of both height and area. The Aravali hills are home to a number of important cities, including Jaipur and Delhi.