You are assigned to create a data model for your new database following the star schema design theory. There is a Table called Table1 which has details about customers. You have noticed that values like email and phone numbers are changed by some of the customers using your application once in a while. There is another table Table2 which stores the salesperson related details. When a Salesperson is relocating to another region, the new version of salesperson details must be created. But the previous version of details must be stored with a start date and end date. Which of the following options is correct? (Multiple Choice)

Answer options:

A.Table1 should use Type 1 SCD
B.Table2 should use Type 2 SCD
C.Table1 should use Type 2 SCD
D.Table2 should use Type 1 SCD

Correct Answer: A and B
Slowly Changing Dimensions (SCD) is used to manage the change in dimension members over a period of time. Some of the dimensions may vary and may not require a previous version also to be available. But some required historical details. 
Here the question says that it is using a star schema design model. Commonly type1 SCD and Type 2 SCD are used with a star schema. 
Table1 has values that may change once in a while and can be overwritten to the current value, instead of creating a new version. This is Type 1 SCD. 
Table2 has a requirement to create a new version of the data, thus Type 2 SCD.Option A is correct: When using the Type 2 SCD, the values are overwritten, and the latest values are only reflected.
Option B is correct: When using Type2, the new version of data is created with start and end dates.
Option C is incorrect: Table1 can afford overwriting of data. So, it is Type1 SCD, not Type2 SCD.Option D is incorrect: Table2 needs versioning, and overwriting will not work here. So, it is TYpe2, not Type1.
Reference: To know more, please refer to the docs below: 

https://docs.microsoft.com/en-us/power-bi/guidance/star-schema#slowly-changing-dimensions