Final answer:
The largest personnel requirement for international marketing is usually found in the sales force, due to the need for customer engagement and market adaptation.
Step-by-step explanation:
The largest personnel requirement for international marketing for most companies is typically in the sales force. The sales team is crucial for establishing a presence in new markets and requires personnel to manage customer relationships, understand local counterparts, and customize sales strategies to different cultures and languages. In contrast, while the management team, finance department, information technology team, and advertising department play significant roles in supporting international marketing efforts, they do not typically match the extensive staffing needs of the sales force in terms of sheer numbers.