A B2B sales startup is creating a customer dimension table. This will be a part of their star schema model. It is used to track customer relations. They collect details like Tax Registration number, mobile phone number, email-id, pincode, etc. There are some instances where the email-id and mobile phone numbers change. Whenever a Customer updates the data at the source, there should be a separate column with a new value and should be kept for the 2 latest versions of this data. Which of the following options says about the most suitable method?

Answer options:

A.Use Type 2 SCD.B.Use Type 1 SCD.C.Use Type 3 SCD.D.Use Type 6 SCD.

Correct Answer: C 
In this type of table, there will be some columns where data once entered will not change. But here, we have to focus on the columns where data will change later. In the question, we have entities like email-id and phone number that should be changed as per the customer`s requirement. This is clearly pointing to the usage of a Slowly Changing Dimension (SCD). 
Type 3 will create a new column with the new version of data that the user has entered. But we should always keep in mind that this SCD is not a commonly used method in the case of tables with a large number of members.
Option A is incorrect: Type to SCDs is mainly for versioning.
Option B is incorrect: This will update the latest values as the source changes.
Option C is correct: Its main purpose is to store the data versions in different columns.
Option D is incorrect: This is a combination of Type 1, 2, and 3 and is not a suitable method.
Reference: 
To know more about SCD Types, please refer to the doc below: 

https://docs.microsoft.com/en-us/learn/modules/populate-slowly-changing-dimensions-azure-synapse-analytics-pipelines/3-choose-between-dimension-types