The direct visual examination of the colon via a flexible,lighted instrument is called:

A) cholangiography.
B) ultrasonography.
C) colonoscopy.
D) cholecystography.

Cholangiography

A diagnostic imaging test used to visualize the bile ducts to identify obstructions, infections, stones, or cancers.

Colonoscopy

A medical procedure that uses a long, flexible tube with a camera on the end to examine the interior of the colon and rectum.

Cholecystography

A radiographic examination of the gallbladder after the administration of a radiopaque contrast medium.