ER-Model

Consider the following relation schema

Students(rollno: integer, sname: string)
Courses(courseno: integer, cname: string)
Registration(rollno: integer, courseno: integer, percent: real)

Which of the following queries are equivalent to this query in English?

"Find the distinct names of all students who score more than 90% in the course numbered 107" 

(I) SELECT DISTINCT S.sname
    FROM Students as S,Registration as R
    WHERE R.rollno = S.roll AND R.courseno = 107 AND R.percent > 90
(II) Πsname(σcourseno=107∧percent>90(Registration ⋈ Students))
(III) {T|∃S ∈ Students, ∃R ∈ Registration (S.rollno = R.rollno ∧ R.courseno = 107 ∧ R.percent > 90 ∧ T.sname = S.sname)}
(IV) {〈SN〉|∃SR∃RP(〈SR,SN〉 ∈ Students ∧ 〈SR,107,RP〉 ∈ Registration ∧ RP>90)}