Final answer:
Oatmeal with nuts is the best protein-rich breakfast option among the choices given, combining the beneficial nutrients of both components.
Step-by-step explanation:
When choosing a breakfast item that is a good source of protein, option C, Oatmeal with nuts, stands out as the best choice among the given options. This choice combines the protein content of nuts with the nutrient-rich profile of oatmeal, making it a substantial and healthy breakfast option. While options like a plain bagel with cream cheese do offer some protein, they lack the diversity and balance of the protein found in nuts. It is also important to note that incorporating substitutions like low-fat or fat-free milk and minimally sweetened cereals with fresh fruit can enhance the nutritional content of breakfast meals. Protein-rich foods for breakfast contribute to a feeling of fullness and provide the necessary energy and nutrients for the day ahead.