Explanation
Tabs allow marketers to customize their Datorama dashboard by adding different widgets and filters. Tabs can also be shared with other users or groups for collaboration. [Source: Trailhead]

Explanation
Einstein STO (Send Time Optimization) Activity is the correct answer. This activity allows you to send an email at the best possible time for each subscriber based on their past engagement behavior. Einstein STO uses artificial intelligence to analyze when each subscriber is most likely to open an email and schedules the send accordingly. This can help increase the engagement rate of your email by reaching your subscribers when they are most receptive. Wait Until Activity is an activity that allows you to pause a journey until a specific date or time, or until a specific attribute value changes. Engagement Split is an activity that allows you to split a journey based on how subscribers interacted with a previous email, such as opening or clicking. You can learn more about these activities in the Journey Builder Activities module on Trailhead.

Explanation
'Update Email Now' needs to be applied to each email that uses the updated template. This option will update the email content with the latest changes from the template. Recreating the email using the updated template would also work, but it would be more tedious and unnecessary. The template does not need to be approved before updates are reflected, but rather saved.

Explanation
Pivot table in Datorama Reports is the tool that NTO should use to explore its large volume of send data. Pivot table allows marketers to dynamically filter, sort, and group data in one view without writing SQL queries. It also allows marketers to create calculated fields and visualize data in charts and graphs. Filter Activity in Automation Studio is used to create filtered data extensions based on criteria, not to explore data in one view.
Email Performance Over Time Report is a standard report that shows metrics for emails sent over a period of time, but it does not allow dynamic filtering, sorting, or grouping of data.

Explanation
Auto Suppression List is the correct answer. An auto suppression list is a list of subscribers who should not receive certain types of emails, such as promotional or transactional emails. Auto suppression lists can be applied at the sender profile level or at the send classification level. If a subscriber is on an auto suppression list that is applied to a triggered send, they will not receive the email, even if they are in the target data extension. The _subscribers data view will show their status as 'Held' for that sender profile or send classification. You can learn more about this in the Manage Subscribers module on Trailhead.