1: Asmaka - Godavari: The Asmaka (or Assaka) was one of the sixteen Mahajanapadas. It was in South India, on the banks of the Godavari Hence pair 1 is correctly matched. 2: Kamboja - Vipas: The Kamboja region was in the northwestern part of the Indian roughly corresponding to parts of Afghanistan, Pakistan, and Kashmir. The river, also known as the Beas, flows through the region. While both are in the northwest, the area of Kamboja is generally placed further west the main course of the Vipas river. Hence pair 2 is correctly matched. 3: Avanti - Mahanadi: The Avanti kingdom was in West-Central India, in the Malwa region of Madhya Pradesh. Its capital was Ujjain. The river flows through Central and Eastern India, in modern-day Chhattisgarh and Odisha. pair 3 is not correctly matched. 4: Kosala - Sarayu: The Kosala kingdom was located the Awadh region of present-day Uttar Pradesh. Its cities were Ayodhya and Sravasti. The Sarayu flows through this region, passing by Ayodhya. pair 4 is correctly matched.