Which statement creates the foreign key?

You need to design a student registration database that contains several tables storing academic
information.
The STUDENTS table stores information about a student. The STUDENT_GRADES table stores
information about the student’s grades. Both of the tables have a column named STUDENT_ID.
The STUDENT_ID column in the STUDENTS table is a primary key.

You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table
that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the
foreign key?

A.
CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa
NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY
students(student_id));

B.
CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa
NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id));

C.
CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa
NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES students(student_id));

D.
CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa
NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES
students(student_id));

Explanation:
CONSTRAINT name FOREIGN KEY (column_name) REFERENCES table_name
(column_name);
Incorrect answer:
Ainvalid syntax
Binvalid syntax
Cinvalid syntax
Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 10-14