Alfresco APSCA - Alfresco Process Services Certified Administrator Certification Examination Exam

Option D is correct because, by default, the Activiti App application uses admin@app.activiti.com as the administrator username for logging into the system. This default administrative account is created during the standard installation and provides full access to manage users, applications, processes, tasks, and system configurations. The other email addresses listed are not the default administrator credentials for the Activiti App. Therefore, the correct answer is Option D (admin@app.activiti.com).