R1 = {(1,1),(1,2), (1,4),(2,1),(2,2), (3,3),(4,1),(4,4)}
R2 = {(2,1),(3,1),(3,2),(4,1),(4,2),(4,3)}
R3 = {(1,1),(1,2),(1,3), (1,4),(2,2), (2,3), (2,4),(3,3), (3,4),(4,4)}
R4 = {(1,1),(1,2),(2,1),(2,2),(3,4),(4,1),(4,4)}
Which of these relations are reflexive and transitive but NOT symmetric?
Select one correct option: