Water, dietary fiber, bacterial cells, and worn-out intestinal cells are components of which of the following?

• A. Blood plasma
• B. Saliva
• C. Urine
• D. Feces

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the components listed in the problem: water, dietary fiber, bacterial cells, and worn-out intestinal cells. These are materials commonly found in the digestive system after food processing.
2. Step 2: Recall the composition and function of each option: blood plasma transports nutrients and wastes in the blood; saliva contains enzymes and water to aid digestion in the mouth; urine is a liquid waste product filtered by the kidneys; feces consist of undigested food, bacteria, and cells shed from the intestinal lining.
3. Step 3: Analyze which option logically contains all the components mentioned. Water is present in all, but dietary fiber is indigestible and passes through the intestines, bacterial cells are abundant in the gut, and worn-out intestinal cells are shed into the digestive tract.
4. Step 4: Recognize that feces are the solid waste expelled from the digestive tract, containing water, dietary fiber, bacteria, and intestinal cells, matching the components listed.
5. Step 5: Conclude that the correct answer is feces, as it uniquely contains all the components mentioned in the problem.