Final answer:
According to the Canada Food Guide, a serving of grain products, such as a whole wheat roll, should be approximately equivalent to a slice of bread. Considering the carbohydrate content, a 25g whole wheat roll is the closest match to a recommended serving.
Step-by-step explanation:
The question refers to the recommended serving size of whole wheat rolls according to the Canada Food Guide (CFG). The CFG suggests filling a quarter of your plate with grain products, like cereals, breads, and pasta. Importantly, it is recommended that half of your daily grain intake should be whole grains. A slice of whole grain bread is about 15 grams of carbohydrates, hence a whole wheat roll, which is roughly equivalent to a slice of bread, would also have about 15 grams of carbohydrates.
When interpreting the given options, it is understood that a 50g roll would contain slightly more than 3 slices' worth of bread based on the carbohydrate contents provided. Since a standard serving would be about 1 slice of bread (15g) or its equivalent, the closest option to a proper CFG serving size would be:
c) 1 roll, 25g