Final answer:
In a decentralized system, the advertising department is typically part of marketing services, responsible for promoting products and creating brand image.
Step-by-step explanation:
Under a decentralized system, the advertising department is generally a part of D. marketing services. Decentralization refers to the distribution of decision-making power throughout an organization. In such a system, the marketing services function typically includes advertising as it focuses on promoting products or services and creating a strong brand image.
Each division or department has autonomy in decision-making related to its functions, which in the case of the advertising department, involves creating and managing ad campaigns aligned with the overall marketing strategies. Under a decentralized system, the advertising department is generally a part of Marketing Services.