After Changing Her Diet to Include a Bowl of Oatmeal

After changing her diet to include a bowl of oatmeal every morning, your aunt Gladys' total blood cholesterol declines from 6.0 mmol/L to 5.8 mmol/L. Which of the following is the most likely explanation for this effect?

A) Oatmeal is a low-fat food and inhibits the body's synthesis of cholesterol.
B) Oatmeal is high in complex fibres that inhibit cholesterol-synthesizing enzymes.
C) Oatmeal consumed on a regular basis suppresses the craving for high-cholesterol foods.
D) Oatmeal is high in soluble fibres that trap bile, causing the body to use more cholesterol for bile replacement.