Consider the following relations for a database that keeps track of auto sales in a car dealership (Option refers to some optional equipment installed on an auto):
CAR(Serial-No, Model, Manufacturer, Price)
OPTIONS(Serial-No, Option-Name, Price)
SALE(Salesperson-id, Serial-No, Date, Sale-price)
SALESPERSON(Salesperson-id, Name, Phone)
First, specify the foreign keys for this schema, stating any assumptions you make. Next, populate the relations with a few example tuples, and then give an example of an insertion in the SALES and SALESPERSON relations that violates the referential integrity constraints and of another insertion that does not.