The river shown on the map is

1. The question asks to identify the river shown on the map. Although the map is not provided here, based on common UPSC questions featuring prominent Southeast Asian rivers, we can analyze the options. 2. The Irrawaddy River flows north-to-south through Myanmar (Burma). 3. The Mekong River is a trans-boundary river in East Asia and Southeast Asia. It flows through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. 4. The Chao Phraya River is the major river in Thailand. 5. The Salween River flows from the Tibetan Plateau south into the Andaman Sea, largely through China and Myanmar, forming a border with Thailand. 6. Without the map, definitive identification is impossible. However, assuming the map showed a major river system flowing through multiple Southeast Asian countries or forming significant borders, the Mekong or Salween are strong possibilities. If the map showed a river primarily within Thailand, it would be the Chao Phraya. If primarily within Myanmar, the Irrawaddy. The provided answer 'd' implies the map showed the Salween River.