Which foods are reliably rich sources of inulin as highlighted in the lesson?

• A. Cooked lean meats and egg whites because animal proteins convert to inulin during digestion and reach the colon intact.
• B. Fresh citrus juices and peeled cucumbers are concentrated inulin sources that primarily reach the colon unchanged.
• C. Refined white bread and glucose syrup are primary sources of inulin and provide high inulin content per serving.
• D. Root vegetables such as onions, garlic, and chicory are reliable inulin sources.

Answer: (D)