Answer:
The correct answer is letter "C": the consumer and customer.
Explanation:
Consumers are individuals who make consumptions on the goods and services markets. The intervention of the merchant might not be necessary for consumers to interact with the goods or services. On the other hand, customers are those who request a good or service from businesses and need their help to acquire the product.
Thus, while purchasing the meatball sub, John is playing the role of the consumer and by ordering of pasta salad he is acting as a customer.