What is the term for when acids in river water dissolve rocks?

The correct term for the process when acids in river water dissolve rocks is "solution." This process involves the chemical interaction between water, which can contain various dissolved acids, and certain minerals in the rocks, leading to the breakdown and removal of rock material. This is particularly significant in areas with limestone or other soluble rocks, where acidic water can lead to the formation of features like caves and sinkholes.

In contrast, corrosion (or abrasion) refers to the physical wearing away of rocks and soils by friction and impact, usually caused by sediment carried by the river. Hydraulic action involves the force of moving water physically breaking rocks apart, while attrition involves the process of rocks colliding against each other and breaking down into smaller pieces. Therefore, these terms describe different processes and do not accurately represent the specific action of acids dissolving rock materials in river water.