What is the function of the Extrude command in sketching?

The Extrude command is an essential tool in sketching, particularly when working with 2D shapes to create 3D objects. Its primary function is to add depth to a 2D shape, transforming a flat profile into a three-dimensional form. This is accomplished by extending the shape perpendicularly along a specified distance to generate a solid object.

When a user selects the Extrude command, they typically start with a 2D sketch depicting the desired geometry. By specifying the extrusion direction and distance, the command effectively thickens the 2D outline into the third dimension, making it possible to create various solid geometries used in engineering and design.

Additional choices may relate to different functionalities in CAD software. For instance, removing material refers to other operations like the Cut or Subtract commands. Enlarging an existing shape might involve scaling features, while creating a circular shape pertains to specific tools that deal with round geometric forms, which do not align with the core purpose of the Extrude command. Hence, the correct interpretation of the Extrude command emphasizes its role in adding depth, confirming C as the correct answer.