Comprehensive and Detailed In-Depth Explanation:Workflow Approval notifications:
* A:The Grid Master (GM) sends emails via its configured SMTP settings (Grid > Grid Properties > Email), as it manages Grid-wide tasks. Correct.
* B:GMC is a standby, not active unless promoted-doesn't send emails. Incorrect.
* C:Only GM sends, not both-GMC is passive. Incorrect.
* D:SuperAdmin is a role, not a process-no sending capability. Incorrect.
* Practical Example:In an INE lab, configure SMTP on the GM, test approval emails, and troubleshoot delivery from GM logs.References:Infoblox NIOS Administrator Guide - Workflow Notifications; INE Course Objective: NIOS DDI Grid Deployment.