What is the correct sentence to express the relationship between the user and his direct manager:

What is the correct sentence to express the relationship between the user and his direct manager: 1. A many-to-many table must be maintained because managers have several employees under them. 2. A field of type reference (foreign key) must be added to the users table with a reference to the record of his direct manager. 3. There is no need to add anything because a manager is also an employee, so we will use the inheritance mechanism. 4. Neither answer is correct. I think the 2nd option is the correct sentence because it suggests using a field of type reference (foreign key) in the users table to establish a direct relationship between a user and their manager