The correct answer is A. Foreign key.
A foreign key is a field in one table that refers to the primary key of another table. In this case, the ‘Student’ field in the ‘Fees’ table refers to the ‘student_id’ field in the ‘Students’ table. This is because the ‘Fees’ table stores information about fees that are paid by students, and each fee is associated with a specific student.
A native key is a primary key that is not a foreign key. A composite key is a primary key that is made up of two or more fields. A primary key is a field or group of fields that uniquely identifies each row in a table.
Here is an example of a foreign key:
| Table | Field |
|—|—|
| Students | student_id |
| Fees | student_id |
In this example, the ‘student_id’ field in the ‘Fees’ table is a foreign key because it refers to the primary key of the ‘Students’ table. This means that each row in the ‘Fees’ table must have a value in the ‘student_id’ field that matches a value in the ‘student_id’ field of the ‘Students’ table.