Final answer:
Sonja is responsible for the business function of management, aligning staffing plans with organizational strategies and goals.
Step-by-step explanation:
The business function for which Sonja is responsible is management. As part of the executive team, Sonja's primary job is to align staffing plans with organizational strategies and goals. This involves evaluating the roles and responsibilities of her direct reports, ensuring that the right people are in the right positions to support the organization's objectives.