Consider the following pairs: River - Flows into 1. Mekong - Andaman Sea 2. Thames - Irish Sea 3. Volga - Caspian Sea 4. Zambezi - Indian Ocean. Which of the pairs given above is/are correctly matched?

1. Mekong – Andaman Sea: Incorrect. The Mekong drains into the South China Sea through the Mekong Delta in Vietnam.
2. Thames – Irish Sea: Incorrect. The Thames flows into the North Sea via the Thames Estuary.
3. Volga – Caspian Sea: Correct. The Volga, Europe’s longest river, empties into the Caspian Sea.
4. Zambezi – Indian Ocean: Correct. The Zambezi flows eastward and drains into the Indian Ocean in Mozambique.

Hence, pairs 3 and 4 only are correctly matched.