How does a pond form? a. a mudflow blocks a river. b. water collects in a low-lying area. c. humans use a dam to create a reservoir. d. a depression made by an ice sheet fills with water.

The right option is; B. Water collects in a low-lying area.

A pond is an inland body of standing water, either man-made or natural, that is smaller than a lake. A pond forms when water collects and fills in a low-lying area (depression) in the ground. Wetland animals and plants can be found in ponds. As the plants inside and around a pond grows, after some time they die and decay. This cause layers of soil in the pond to accumulate which in turn makes the pond to become shallower.