Final answer:
The nurse leader is promoting self-management in the client by teaching exercises that can be performed during daily activities.
Step-by-step explanation:
The nurse leader in this scenario is following Gardner's leadership task of promoting self-management in the client. By teaching the client different exercises that can be performed while working in an office or doing daily activities, the nurse is empowering the client to take control of their own health and manage their leg pain. This encourages the client to be active and make healthy choices, which can relieve the pain and improve their overall well-being.