With reference to ancient India (600-322 BC), consider the following pairs:Territorial Region River flowing in the regionI.Asmaka : GodavariII.Kamboja : VipasIII.Avanti : MahanadiIV.Kosala : SarayuHow many of the pairs given above are correctly matched?

1. A

   Only one

   Only one. Asmaka–Godavari holds, and one more pair is keyed with it.

2. B

   Only two

   Only two. Asmaka on the Godavari and Kosala on the Sarayu are the scored matches. Kamboja is not Vipas; Avanti is not Mahanadi.

3. C

   Only three

   Only three. That keeps a false river pairing.

4. D

   All the four

   All four. Two pairs fail.

Summary. Official Set A key is (b) only two. Asmaka (Assaka) sits on the Godavari. Kosala is the Sarayu country. Kamboja is the north-west, not the Beas (Vipas). Avanti is the Malwa–Narmada/Chambal world, not the Mahanadi. So two pairs are right, not one and not three.