Consider the following list of requirements related to a large enterprise with several companies, for which you are required to come up with an ER model. Each company operates four departments, and...

Consider the following list of requirements related to a large enterprise with several companies, for which you are required to come up with an ER model.

1. Each company operates four departments, and each department belongs to one company.


2. Each department in part (a) employs one or more employees, and each employee works for one department.


3. Each of the employees in part (b) may or may not have one or more dependents and each dependent belongs to one employee.


4. Each employee in part (c) may or may not have an employment history, which includes his employments until the employee joined this enterprise as well as the employment history within the enterprise (after joining).

Which of the following statements are true about the ER diagram (assuming it is a good design)?

1. Employment history will be a weak entity.


2. There will be a many-to-many relationship between company and employee.


3. The relationship between department and employee will be optional for department