Which relationship is possible when two tables share the same primary key?

A. one-to-one

B. one-to-many

C. many-to-one

D. many-to-many

When two tables share the same primary key, they share a

A. one-to-one relationship.

Explanation:

One-to-one relationship is a type of cardinality that refers to the relationship between two entities A and B in which one element of A may only be linked to one element of B, or the opposite way. A one-to-one relationship in a relational database occurs when one parent record or field has either zero or one child record only. These relationships are the easiest to represent in databases because both the parent and child records may be in the same table. One-to-one relationships associate one record in one table with a single record in the other table. These relationships are frequently used to indicate critical relationships so you can get the data you need to run your business. A one-to-one relationship is a link between the information in two tables, where each record in each table only appears once.