Which of the following describes the natural flow of water due to tidal movements?

The natural flow of water due to tidal movements is best described by the term "current." Tidal currents are the horizontal movements of water that occur as a result of the periodic rise and fall of sea levels caused by gravitational forces from the moon and the sun. These currents can vary in speed and direction depending on the geographic location and the phase of the tide.

Lagoon refers to a shallow body of water separated from a larger body of water, typically along a coast, and does not inherently describe the movement of water. Reservoir describes a storage area for water, usually created by damming rivers, which does not pertain to the natural flows caused by tides. Stream refers to a body of flowing water, typically freshwater, that moves in a defined channel; while it involves flow, it is not specifically related to tidal movements like currents are.

Therefore, the correct choice reflects the dynamic nature of water flow driven by tidal forces, which is encapsulated by the term "current."