Which of the following statements best describes dietary fiber, its health benefits, and common food groups that are high in fiber?

Dietary fiber consists mainly of non‑digestible plant carbohydrates that increase stool bulk and speed intestinal transit; high amounts occur in whole grains and some vegetables.

Dietary fiber refers to indigestible plant components that support digestive health, help regulate postprandial blood glucose and LDL cholesterol, and are abundant in whole grains, fruits, vegetables, and legumes.

Dietary fiber includes fermentable oligosaccharides and resistant starches that are metabolized by gut microbiota to produce short‑chain fatty acids, commonly found in legumes, cooked‑then‑cooled potatoes, and certain processed fiber‑enriched foods.

Dietary fiber comprises soluble fibers that form viscous gels and may slow nutrient absorption; foods relatively high in this fraction include oats, barley, legumes, and some fruits.