Create an entity relationship diagram for each of the following subtasks a) to d). Note: The subtasks a) to d) are independent of each other and should be considered individually.
a) A person is described by first name, last name and a unique personnel number. Customers are persons for whom a customer number and an acquisition date are also given. The latter states since when the person has been a customer. Employees are people for whom a contract number and a contract period should also be saved.
b) Information about customers and vehicles is stored in the reservation system of a vehicle rental company. A unique license plate number and a vehicle type are specified for a vehicle. Customers are described by a unique customer number, first name and last name. Customers reserve vehicles in the office. A vehicle can be reserved by different customers with different reservation dates. There may also be vehicles without reservations. A customer must have reserved at least one vehicle. A reservation date should be specified for each reservation.
c) A member is described by their first name, last name and a unique membership number. A member can have a membership card, each membership card must be assigned to exactly one member. A unique ID number, a start and end date of validity and a club function of the member are specified for a membership card.
d) Students are described by a first name, last name and date of birth. Students may have siblings who are also students. Create an ERD. What options are there for meaningfully defining the primary key for the student entity.