Given only the following excerpt of an E-R model:

Which of the following is known to be true?
A) There are more instances of ENTITY A than there are instances of ENTITY B in the user's environment.
B) A single instance of ENTITY B may be related to many instances of ENTITY A.
C) A single instance of ENTITY A must be related to many instances of ENTITY B.
D) ENTITY A has a minimum cardinality of one.
E) The degree of the relationship is "many."

Question

Given only the following excerpt of an E-R model:

Which of the following is known to be true?
A) There are more instances of ENTITY A than there are instances of ENTITY B in the user's environment. 
B) A single instance of ENTITY B may be related to many instances of ENTITY A. 
C) A single instance of ENTITY A must be related to many instances of ENTITY B. 
D) ENTITY A has a minimum cardinality of one. 
E) The degree of the relationship is "many."

Quizplus · Accepted Answer

The symbol "TB" likely represents a table in a database, and "4534" may be an identifier for the table. The string of characters before the table identifier likely represents a relationship between two entities in the database. The fact that there is a reference to an ENTITY A and an ENTITY B indicates that there are at least two types of entities in the database, and the use of the term "related" suggests that there is a relationship between them. The string of characters includes a code for a relationship and an identifier for the table, but there is no information provided about the nature of the relationship or the cardinality of the entities. However, the inclusion of "many" in the string suggests that there is a possibility of many instances of ENTITY A being related to a single instance of ENTITY B, indicating a one-to-many relationship. Therefore, choice B is the best option since it reflects this possibility.

Given Only the Following Excerpt of an E-R Model