With respect to relational databases, which of the following statement(s) is (are) true?

a. A foreign key is only found in one table; it is not allowed to be in another table.

b. When data about objects of interest are stored in separate database tables, it is easier to avoid insert anomalies.

c. According to the entity integrity rule, a primary key can uniquely identify a table row if it is blank.

d. An insert anomaly occurs when there is no way to update records to a database.

e. Semantic data modeling uses a system designer’s knowledge of business processes to create tables in 3NF.