Egbert lives on a lakefront property in an area suffering from a ten-year drought. The lake's water level has gone down during the drought, making his property's land mass larger. What is this process called?

Accession refers to the legal principle where property rights are extended to include natural or artificial additions to a landowner's property, such as buildings or trees. While it involves the enhancement of property, it does not specifically pertain to changes in land mass due to water level fluctuations, making it an incorrect choice in this context.

Erosion is the process of soil and rock being worn away and transported by natural forces such as wind or water. In contrast to reliction, which involves the exposure of land due to receding water levels, erosion results in the loss of land. Therefore, this choice does not apply to Egbert's situation.

Avulsion refers to a sudden and noticeable change in land boundaries, often due to natural events like floods or landslides that shift land from one property to another. While it deals with changes in land due to water, it is not the gradual process described in the scenario and is therefore not the correct answer.