What is a primary key? a field that uniquely identifies a record in a table a field that uniquely identifies a table the first security key entered by a database user the first security key entered by a database administrator

The correct answer is letter "A": a field that uniquely identifies a record in a table.

Explanation:

A primary key is a unique relational database table that is created to identify record tables. Primary keys contain a special value for each row of data and it does not include "null" data. Typical information recorded in primary key tables are individual's telephone numbers, insurance policy numbers or bank account numbers.

answer(d) sequencing and iteration;

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