Which characteristic is typical of an exotic stream?

• A. Fed by a region of much higher precipitation
• B. Flows solely through mountainous terrain
• C. Has many tributaries flowing into it
• D. Relies on glacial melt for its water supply

Answer: (A)

An exotic stream is defined by its ability to maintain a significant flow of water despite being located in an area that lacks abundant water sources, often in arid or semi-arid regions. The key characteristic of an exotic stream is that it is typically fed by a region that experiences much higher precipitation than the area it traverses. This means that while the stream may flow through dry regions, its source is from a considerably wetter area, allowing it to sustain its flow over greater distances.

The other characteristics mentioned don't accurately depict the defining nature of an exotic stream. For instance, not all exotic streams flow exclusively through mountainous terrain; they can traverse various types of landscapes. Furthermore, while some may have tributaries, this is not a requirement for a stream to be classified as exotic. Similarly, relying on glacial melt is specific to certain streams, particularly those found in glaciated regions, but it does not align with the criteria for exotic streams as a general characteristic. Thus, the correct choice highlights the essential feature of a significant upstream precipitation source, which characterizes exotic streams.