where do rivers usually begin? at the ocean at groundwater outlets in mountainous regions in lakes and larger rivers

Rivers usually begin in mountainous or hilly regions, where rain and melting snow gather into small streams that flow downhill and join together. The correct choice is: in mountainous regions.

Why mountainous regions?

• Mountains are high, so gravity pulls water downhill, forming streams that grow into rivers.

• These areas often receive heavy rainfall and/or snow, which provides a steady water supply to start rivers.

What about the other options?

• At the ocean: Rivers usually end in oceans, not begin there.

• Groundwater outlets: Springs can start small streams, but the classic, most common river origins are in upland or mountainous catchment areas.

• Lakes and larger rivers: Some rivers flow out of lakes, but those lakes are typically fed by streams that began in higher ground, often mountains.

So, among the choices given, “in mountainous regions” is the best and most accurate answer.