A client is admitted for medical management of a bowel obstruction. The drainage volume from the nasogastric tube over the last 12 hours is 300 milliliters. Which assessment finding provides the earliest indication that the client is experiencing gastrointestinal motility?

A. Normalized electrolytes are important but do not specifically indicate gastrointestinal motility. B. Decreased nausea can be a sign of improvement but is less specific than passing flatus. C. Passing flatus indicates that there is movement of gas through the intestines, which is a direct sign of returning gastrointestinal motility. D. Return of appetite can occur for various reasons and is not as direct an indicator of GI motility as passing flatus.