[! ] as stream discharge increases, which of the following occurs? a. stream velocity increases, but channel width and depth both decrease. b. stream velocity decreases, but channel width and depth both increase. c. stream velocity, channel width, and depth all decrease. d. stream velocity, channel width, and depth all increase.

The correct answer is - D. Stream velocity, channel width, and depth all increase.

When a stream is faced with a sudden increase of water, than the stream starts to increase its velocity. The velocity is becoming greater in the lower part of the stream. As the velocity increases, it is followed by an increase in width of the stream because it starts to flood the surrounding area, and also, because of the much increased amount of water in the stream, it increases its depth as well.