**Core Concept:** Glycemic index (GI) is a ranking of carbohydrate-containing foods based on the extent to which they raise blood glucose levels when consumed. Foods with a high GI are rapidly digested and absorbed, causing a rapid increase in blood glucose levels, while foods with a low GI are slowly digested and absorbed, leading to a gradual increase in blood glucose levels.

**Why the Correct Answer is Right:** The correct answer is **D** because it refers to the most commonly used reference food, which is white bread, having a GI of 100. Fruits are compared to this reference food to determine their GI values. Fruits' GI values are generally lower than white bread's, indicating that they cause a slower and less significant rise in blood glucose levels.

**Why Each Wrong Option is Incorrect:**

A. **Low Glycemic Index (GI) foods**: While this statement is true, the correct answer should specifically mention the reference food, white bread, as having a GI of 100.

B. **High Glycemic Index (GI) foods**: This statement is partially true, but the reference food (white bread) and its GI (100) are essential for a complete understanding of food's GI value.

C. **Low Glycemic Load (GL) foods**: Glycemic Index (GI) and Glycemic Load (GL) are interconnected concepts, but the question specifically asks about GI. Glycemic Load considers both GI and the serving size of the food, making it irrelevant for the given question.

**Clinical Pearl:**

Understanding food GI values helps in making informed dietary choices, particularly for individuals with diabetes, obesity, or other glucose regulation-related conditions, as they can adjust their diet to maintain better glycemic control while enjoying a balanced diet. A low GI diet promotes satiety, reduces postprandial glucose spikes, and may lead to better long-term weight management.