Understand that proteins, carbohydrates, and fats are macronutrients that provide energy in the form of calories.
Recall that each macronutrient provides a specific amount of calories per gram: carbohydrates and proteins provide 4 calories per gram, while fats provide 9 calories per gram.
Identify the options given in the problem: 7 calories per gram, 11 calories per gram, 9 calories per gram, and the correct answer, 4 calories per gram.
Recognize that the problem is asking for the caloric value of protein, which is a fundamental concept in nutrition and biochemistry.
Conclude that the correct caloric value for protein is 4 calories per gram, based on standard nutritional information.