Final answer:
The percentage of protein intake served at breakfast is 32%. Therefore the correct answer is option b.
Step-by-step explanation:
The USDA recommends the following grams of protein for breakfast, lunch, and dinner daily: 17g breakfast, 20g lunch,16g dinner. To determine the percentage of total protein intake served at breakfast, we need to calculate the total grams of protein consumed in a day and divide it by the protein intake at breakfast.
In this case, the total protein intake is 17g + 20g + 16g = 53g.
Therefore, the percentage of protein intake served at breakfast is (17g / 53g) * 100% = 32%