Given the relational database below.

a$-)$what are the referential integrity constraints in this model? Write them in the form of FK $$ PK

Hint: A PK may consist of more than one attribute.

b$-)$Transform this relational databese model to its equivalent $\frac{E}{R}$ model. Hint : Notice which tables

transform to entities and which tables to relationships. Don't forget specify the cardinality constraints.