Final answer:
One serving size of a muffin, according to CFG servings for grain products, is a small muffin weighing 60 grams.
Step-by-step explanation:
The question relates to the serving size of grain products, specifically regarding how much of a muffin constitutes one serving. According to dietary guidelines and nutritional information, a typical serving size for grain products like muffins would align with a smaller portion rather than a larger one. Hence, the answer to the question '1 CFG Servings: Grain Products - how much of a muffin?' would be a) 1 small muffin, 60g. This serving size is a balanced portion that helps to maintain a healthy diet and manage caloric intake.