UPSC Prelims 2020— Question 78

This question tests river-sea matching. The key concept is: The Volga flows into the Caspian Sea and the Zambezi flows into the Indian Ocean, while the Mekong empties into the South China Sea and the Thames into the North Sea. Therefore the correctly matched pairs are 3 and 4. The verified answer for the uploaded Set-B paper is option C. Option A — 1 and 2 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: The Volga flows into the Caspian Sea and the Zambezi flows into the Indian Ocean, while the Mekong empties into the South China Sea and the Thames into the North Sea. Therefore the correctly matched pairs are 3 and 4. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. Option B — 3 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: The Volga flows into the Caspian Sea and the Zambezi flows into the Indian Ocean, while the Mekong empties into the South China Sea and the Thames into the North Sea. Therefore the correctly matched pairs are 3 and 4. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. Option C — 3 and 4 only: This is the correct option. It matches the verified conclusion because The Volga flows into the Caspian Sea and the Zambezi flows into the Indian Ocean, while the Mekong empties into the South China Sea and the Thames into the North Sea. Therefore the correctly matched pairs are 3 and 4. The wording of the option is consistent with the governing concept tested by the question. Option D — 1,2 and 4 only: This is not the correct option. The option does not match the verified combination or conclusion. The decisive point is the distinction explained above: The Volga flows into the Caspian Sea and the Zambezi flows into the Indian Ocean, while the Mekong empties into the South China Sea and the Thames into the North Sea. Therefore the correctly matched pairs are 3 and 4. Therefore this alternative should be eliminated even if part of its wording appears plausible in isolation. For UPSC-style elimination, first identify the exact proposition being tested, then evaluate each statement independently before comparing the answer codes. Avoid treating a broad or absolute statement as correct merely because its general theme is familiar. The precise qualifiers in the question—such as 'all', 'only', 'cannot', 'largest', 'always' or a specific institutional role—often determine the answer. On that basis, option C is the verified answer.