The administrator can add a stretched VLAN in NDB using either static or dynamic VLANs. A stretched VLAN is a VLAN that spans across multiple Nutanix clusters, and allows the NDB-managed databases to communicate and migrate between different clusters. A static VLAN is a VLAN that is manually configured and assigned to the database server VMs and the databases by the administrator. A dynamic VLAN is a VLAN that is automatically configured and assigned to the database server VMs and the databases by the NDB instance, using the Nutanix Calm orchestration service. Both static and dynamic VLANs can be used to create a stretched VLAN in NDB, as long as they have the same VLAN ID and network configuration across the clusters.
The administrator cannot add a stretched VLAN in NDB using only VLANs that are not managed in NDB. A VLAN that is not managed in NDB is a VLAN that is configured and assigned to the database server VMs and the databases outside of the NDB instance, using the Nutanix Prism web console or other tools. A VLAN that is not managed in NDB cannot be used to create a stretched VLAN in NDB, as it is not recognized or controlled by the NDB instance.
References:
* Nutanix Database Management & Automation Training Course, Module 4: Nutanix Era Configuration, Lesson 4.1: Nutanix Era Configuration, slide 8.
* Nutanix Database Management & Automation Training Course, Module 6: Nutanix Era Disaster Recovery, Lesson 6.1: Nutanix Era Disaster Recovery, slides 6-7.

According to the Nutanix Database Automation (NCP-DB) learning documents, the Schedule feature of the Time Machine allows developers to automate the data refresh for their clones1. This feature eliminates the time-consuming, complex process of database clone/refresh, allowing admins to create database clones/refresh to any point in time in just a few minutes1. Please refer to the official Nutanix documentation and training materials for more detailed information2.

The correct answer is B and D because these are the two status values that can be set within the Alerts Dashboard in NDB. Resolved means that the alert has been fixed and no longer requires attention.
Acknowledged means that the alert has been seen and is being worked on. Option A is incorrect because Auto is not a status value, but a mode that automatically resolves alerts based on predefined rules. Option C is incorrect because Data Resiliency is not a status value, but a feature that ensures the availability and integrity of the data in NDB.
References: The following sources provide more information about the Alerts Dashboard and its status values in NDB:
* Nutanix Database Management & Automation (NDMA) course, Module 3: Monitoring Alerts and Storage Usage Within an NDB Implementation, Lesson 3.1: Monitoring Alerts
* Nutanix Certified Professional - Database Automation (NCP-DB) v6.5, Knowledge Objectives, Section
3 - Monitor Alerts and Storage Usage Within an NDB Implementation
* Nutanix Database Service (NDB) User Guide, Chapter 3: Monitoring Alerts and Storage Usage Within an NDB Implementation, Section 3.1: Monitoring Alerts
* [Nutanix Support & Insights], Resolving All Alerts Related to a Database or Database Server VM in NDB

According to the Nutanix Database Automation (NCP-DB) learning documents, to configure Era to send alert notifications to email recipients, you need to go to the Administration section, select Era Service, then go to the configure notification widget. From there, you can update the SMTP server configuration1. This allows Era to use the SMTP server to send alert notifications to the specified email recipients1.

The NDB GUI allows an administrator to set the schedule interval for a database log catch up, which is the process of collecting transaction logs periodically from the source databases and storing them in the time machine. The shortest possible value for this interval is 15 minutes, as per the NDB documentation1. This means that the NDB time machine will capture the database logs every 15 minutes and use them for backup, restore, clone, and refresh operations. References: Nutanix Database Management & Automation (NDMA), page 29; Nutanix Support & Insights, section "Log Catch-up"