🔍 Key Concepts

• Consider what each structure is designed to do along a river bank: protect, deflect current, or change the river’s course. • Think about the shape and orientation: the question mentions extending from the bank at right angles to the current. • Review the common riverbank structures: cutoff, revetment, dike, and crib, and how they interact with water flow.

💭 Think About

• Which of these terms refers to a structure that sticks out into the water from the bank, rather than lying along the bank? • Which structure is mainly used to protect the bank surface from erosion and usually runs parallel to the shoreline? • Which terms are more associated with changing the river’s path or enclosing/containing material rather than just projecting into the current?

✅ Before You Answer

• Identify which option specifically refers to a structure built to project into the stream to influence current and reduce bank erosion. • Eliminate any option that normally describes a structure running along the bank instead of outward from it. • Confirm that the chosen term is commonly built of stone or pilings and located at about a right angle to the river flow.