The correct answer is 1, 2 and 3 Key Points In Mahajanapadas Forts were probably built because people were afraid of attacks from other kings and needed protection. It is also likely that some rulers wanted to show how rich and powerful they were by building really large, tall and impressive walls around their cities. The new rajas now began maintaining armies. Soldiers were paid regular salaries and maintained by the king throughout the year. As the rulers of the mahajanapadas were (a) building huge forts (b) maintaining big armies, they needed more resources. Hence, statement 1 and 2 is correct. And they needed officials to collect these. Hence, statement 3 is correct. So, instead of depending on occasional gifts brought by people, as in the case of the raja of the janapadas, they started collecting regular taxes. Additional Information The list below provides you with the names of 16 Mahajanapadas Kasi Kosala Anga Magadha Vajji Malla Chedi Vatsa Kuru Panchala Matsya Surasena Assaka Avanti Gandhara Kamboja [ alt="16-Mahajanapadas" mahajanapadas map src="https://cdn1.byjus.com/wp-content/uploads/2020/08/16-Mahajanapadas.png" style="width: 455px; height: 350px;">