Under which condition does the water of a river system fail to reach the sea?

Correct answer: When the river ends in a lake or sandy area in inland drainage

The direct answer is B, when the river ends in a lake or sandy area in inland drainage. A drainage system is inland when its water does not reach an ocean or sea. Instead, the river may end in a lake, marsh, salt depression or sandy desert area, where water evaporates, seeps into the ground or disappears among the sediments. Option B is correct because it describes exactly this condition. The Luni is a familiar Indian example: it flows through an arid region and its water may terminate inland rather than reaching the sea as a continuous river. Option A is incorrect because having many tributaries generally adds water to the main river; it does not by itself prevent the river from reaching the sea. Option C is incorrect because a Himalayan origin does not automatically mean inland drainage; many Himalayan rivers, such as the Ganga and Brahmaputra, ultimately reach the sea. Option D is incorrect because a delta forms where a river deposits sediment near its mouth, usually before entering a sea or lake; delta formation normally indicates that the river has reached its lower course, not that it necessarily fails to reach the sea. The reasoning is: no sea outlet plus termination in a closed lake or sandy depression equals inland drainage. Remember “inland drainage ends inside the land.” Do not confuse a river ending in a lake with a river forming a delta; both involve deposition, but their drainage outcomes differ.