What procedure requires using a control body in flexible endoscopy?

The procedure of illumination of the view in flexible endoscopy requires the use of a control body because it involves manipulating the light source to enhance visibility during the examination. The control body serves as a crucial component in managing the optical systems, ensuring that light properly illuminates the area being observed. This ability to control illumination is vital for the accurate visualization of anatomical structures, detection of abnormalities, and guiding other procedural actions. In flexible endoscopy, proper lighting is paramount for successful diagnostics and interventions, making the control body an essential tool for this procedure.

While other options may involve elements of flexibility and control, they do not specifically relate to the manipulation of light, which is the primary function fulfilled by the control body in this context.