Which of the Following Is True When Representing a 1:1

Multiple Choice

Which of the following is true when representing a 1:1 binary relationship using the relational model?

A) The key of the entity with the highest minimum cardinality must be placed in the other entity as a foreign key.
B) The key of each entity must be placed in the other as a foreign key.
C) The key of either entity is placed in the other as a foreign key.
D) The key of the entity with the most attributes must be placed in the other entity as a foreign key.
E) Both entities must have the same primary key.