Final answer:
The correct answer is B, the owner is in violation of the law if the required permits were not obtained. This could lead to legal action requiring the removal of the barn and restoration of the marshland.
Step-by-step explanation:
The owner of a residential property who fills in a marsh to build a barn without the required permits is in violation of environmental and land-use regulations. The owner cannot fill in the marsh completely as he believes that it was caused by overflow of water caused by the beaver dam. The correct action for the owner would be to not destroy the beaver dam and also place a retaining wall to prevent further encroachment of the marshland.
In many jurisdictions, marshlands are considered wetlands, which are protected due to their ecological importance, including serving as habitats for wildlife, filtering pollutants from water, and acting as buffers against flooding. The Environmental Protection Agency (EPA) and local governing bodies typically require permits for activities that alter such areas. Without these permits, the owner could be subject to legal action, including being required to remove any structures built and restoring the marshland to its original state.