Correct Answer: (b) Atranjikhera
Solution:Atranjikhera is a prehistoric and historic excavated archaeological site on the bank of Kali river, a tributary of Ganga. This site was first identified by Sir Alexander Cunningham in his survey report in 1861-62 but excavated by R.C. Gaur. A Trial trench put in 1962, was followed in the next year by digging an a small scale. Regular excavation was started in 1964. The earliest evidence of iron used in the region dated back to around 1000 B.C.