You need to create a custom Dataverse table that would contain phone call log information, like call date, start and end time, phone number, and a short description of the call`s purpose. 
What will be the best table type to store such information?

Answer options:

A.Standard
B.Virtual
C.Regular
D.Activity
E.Temporary

Correct Answer: D 
Dataverse provides the three types of tables (entities): Standard — this is a usual custom table type user can create. These tables store data and navigation for model-driven apps.
Activity — this is a special custom table type for storing activity information like appointments, phone calls, emails, tasks, etc.
Virtual — this custom table type has columns that bring data from external sources, like Azure SQL Database or Azure Cosmos DB.
If you need to store activity information, you need to use an activity table type. This type creates columns that help you properly store the data, such as start and end time, duration, due date. Also, Dataverse provides columns to capture the activity purpose, like subject and description. 
When you select the Activity type for the new table (Number 1), the Dataverse automatically creates and locks a Primary Name Column with a "Subject "for a Display name (Number 2) and internal column Name (Number 3). The system also locks the table ownership to "User and team" (Number 4) because an Organization cannot own activity tables. 

All other options are incorrect. 
For more information about Dataverse table types, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/maker/data-platform/types-of-entities
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/activity-entities