The correct option is (a).
Explanation
The period of the Mahajanapadas (c. 6th century BCE) marks the era of the Second Urbanization in Indian history. This period witnessed the transition from tribal polities to large territorial states, characterized by the emergence of distinct urban centers and organized state administration.
Statement-wise Analysis:
- Statement 1 is Correct: Most Mahajanapadas had a designated capital city which functioned as the administrative, political, and economic center of the state. Prominent examples include Rajgriha (Magadha), Shravasti (Kosala), and Kaushambi (Vatsa).
- Statement 2 is Correct: Due to frequent conflicts and the need for security, many of these capital cities were fortified. Huge walls were constructed around the cities to protect the people and the rulers from attacks by other kings.
- Statement 3 is Incorrect: The fortification walls were constructed using a variety of materials depending on availability and resources. Archaeological evidence confirms that walls were built of wood, brick, stone, and mud. The assertion that they were "always made exclusively of stone" is historically inaccurate. For example, wooden palisades were a common feature in the Gangetic plains.
Key Takeaway:
The rise of Mahajanapadas is defined by the development of fortified capital cities. These fortifications utilized diverse construction materials-including wood, mud, and brick-rather than being limited solely to stone.