Which river, originating in the Iran Mountains of Kalimantan and flowing for 563 kilometres through Sarawak, is the longest river in Malaysia?

• A Rajang River ✓
• B Kinabatangan River
• C Baram River
• D Pahang River

The Rajang River (Batang Rajang) is the longest river entirely within Malaysia; it is a vital transport artery for Sarawak's interior, serving timber camps and longhouse communities inaccessible by road.