auto generated identity field as business key

I have 4 Fields let's say tab_id, Col_A,Col_B,Col_C, Start_Date, End_Date  in source table .

In building a dimension

Tab_Id is not a unique field that classifies as a business key.

Col_A,Col_B,Col_C are all required SCD.

Can I add an auto generated number as a business key in source table to use as the business key in dimension table?

or can I create  a composite business key using the fields  tab_id, Col_A,Col_B,Col_C while still keeping  Col_A,Col_B,Col_C as SCD?

Thanks,