Text: It later became the capital of the Mauryan emperors, in the third century b.c. , and one of the largest cities in the world at 3 km (2 miles) acroseand 12 km (7 miles) along the Ganga.
Entailment: In the third century B.C., it became the capital chosen by Mauryan emperors.
Contradiction: The city was never the capital for Mauryan emperors.