Consider the set of relations shown below and the SQL query that follows.
Students: (Roll_number, Name, Date_of_birth)
Courses: (Course_number, Course_name, Instructor)
Grades: (Roll_number, Course_number, Grade)
Select distinct Name
from Students, Courses, Grades
where Students.Roll_number=Grades.Roll_number
and Courses.Instructor = 'Korth'
and Courses.Course_number = Grades.Course_number
and Grades.Grade = 'A'
Which of the following sets is computed by the above query?
 Names of students who have got an A grade in all courses taught by Korth

Names of students who have got an A grade in all courses

Names of students who have got an A grade in at least one of the courses taught by Korth

None of the above