Tributary Definition Explained
The question asks for the correct definition of a 'tributary'. Let's analyze the options:
- Option 1: A river flowing into a larger river - This is the standard definition of a tributary. A tributary is a stream or river that flows into a larger stream or main stem river (or a lake).
- Option 2: A body of salty water mixing with river water - This describes an estuary, where freshwater meets seawater.
- Option 3: A lake at the river's mouth - This is not the definition of a tributary.
- Option 4: A river branching away from another - This describes a distributary, which carries water away from the main river channel, typically towards a delta.
Correct Tributary Identification
Based on the analysis, the correct definition is that a tributary is a river flowing into a larger river.
Therefore, Option 1 is the correct answer.