Consider the instance of the Students relation shown in the table below. Assume these tuples are stored in a sorted file in the order shown. Each page can store up to two tuples. Sid Name Age gpa 60 1 A 19 2 B 20 90 3 18 80 D 19 70 5 E 20 90 6 F 21 60 Construct a clustered index on gpa using Alternative (2) (i.e. by reference)