Final answer:
The weight of a half romaine head cannot be determined based on the given information.
Step-by-step explanation:
To determine how much a half romaine head weighs for use in making a Blue Ridge Salad, we need to refer to the given information. The example provided states that each salad requires 7 tablespoons of Romano cheese. Since the question asks for the weight of a half romaine head, we cannot determine the exact weight based on this information alone. Therefore, the correct answer cannot be determined from the options (a. 4-5 oz, b. 5-6 oz, c. 6-7 oz, d. 7-8 oz) provided in the question.