please answer with a full explanation

1. When creating a database in Microsoft access

1. Foreign keys must be specified for each table.
2. In access it is impossible to create a table without designing a primary key.
3. All data and three problems resulting error messages.
4. Referential integrity is only enforced for those relationships for which the database design or user places a check mark in a box for enforce referential integrity during or after creation of the relationship in the relationship layout.
5. To delete a relationship, simply deleting one of the tables involved in the relationship will do the trick.