Given the following two tables, which JOIN operation should be used in the blank to ensure the query returns all students, including those not enrolled in any course, with their course_id if available?

SELECT students.name, students.age, enrollments.course_id
FROM students
_____________ enrollments
ON students.student_id = enrollments.student_id

SELECT students.name, students.age, enrollments.course_id
FROM students
_____________ enrollments
ON students.student_id = enrollments.student_id