Consider three tables in a relational database:

$1-$ Students Table:

Students $($student$\_$id $($PK$),$ student$\_$name, age, grade$)$

$2-$ Courses Table:

Courses $($course$\_$id $($PK$),$ course$\_$name, instructor$)$

$3-$ Enrollments Table:

Enrollments $($enrollment$\_$id $($PK$),$ student$\_$id $($FK$),$ course$\_$id $($FK$),$ enrollment$\_$date$)$

What is the output of the following SQL statements:

Question $3$

Not yet

answered

Marked out of

Flag question

SELECT AVG$($grade$)$ FROM Students GROUP BY age HAVING COUNT$(*)>1$;

Select one:

a$.$ Average grade of students with the same age

b$.$ No output

c$.$ Average grade of all students

d$.$ Total number of students