Which key retains its uniqueness even after you remove some of the fields?

the retains its uniqueness even after you remove some of the fields.

Primary key retains its uniqueness even after you remove some of the fields.

Explanation:

I am assuming that this question is related to database. Therefore, I am answering it according to database context.

In database, you can have multiple rows and columns. Each column shows a specific attribute while each row plots the data according to the attributes. However, there is the first column of each of main table that has unique set of values. It is called the Primary Key. Some key features of primary key are:

Therefore, the primary key has the ability to retain its uniqueness even after you remove some of the fields.