The correct answer is C. the Microsoft 365 admin center . Microsoft Learn documents a specific Copilot image generation setting in the Microsoft 365 admin center under Copilot > Settings > Copilot actions > Copilot image generation . Microsoft states that when this scenario is allowed, users can ask Copilot to create, design, and edit images. When it is not allowed, Copilot does not generate images and instead responds with stock or brand images. This directly matches the requirement to prevent users from generating images by using Copilot.

The other options are incorrect because Microsoft does not document this control as being managed from Defender, Purview, or Entra for this scenario. Microsoft also separately notes that organizations can control access to Designer image generation through policy, but the admin experience for managing the Microsoft 365 Copilot scenario itself is explicitly surfaced in the Microsoft 365 admin center . Therefore, for an exam question focused on where an admin should go to disable image generation in Copilot, the best and documented answer is the Microsoft 365 admin center .