What makes up most of the solid waste of feces? A. Undigested food B. Bacteria and fiber C. Dead body cells D. Metabolic waste

The composition of solid waste, particularly feces, is primarily made up of various materials from the digestive process. Let's analyze the options:

1. Undigested Food: While feces do contain undigested food, it is not the predominant component.

2. Bacteria and Fiber: A significant portion of feces is composed of bacteria, which are essential for digestion, alongside dietary fiber that the body cannot digest. This combination makes up a large portion of fecal mass.

3. Dead Body Cells: This option signifies a small contribution from sloughed-off cells from the intestinal lining but is not the main component.

4. Metabolic Waste: This refers to waste products generated from the body's metabolic processes; however, it constitutes a smaller fraction of feces.

Among these choices, option B. Bacteria and fiber is the most accurate, as they form a significant part of fecal matter. Therefore, feces is primarily made up of a mixture of bacteria and dietary fiber, which aids in the digestive process and adds bulk to the waste.