Final answer:
The balanced scorecard is a tool that helps HR leaders evaluate the effectiveness of HR activities.
Step-by-step explanation:
The tool that will help the HR leader evaluate the effectiveness of HR activities is the balanced scorecard. The balanced scorecard is a strategic performance management tool that measures an organization's performance across four key areas: financial, customer, internal processes, and learning and growth. By using this tool, the HR leader can assess how HR activities contribute to the overall strategy of the organization and make necessary adjustments.