HELP PLEASE!!

Is the relation a function?

Select Yes or No for each relation.

Relation Yes No
(2, 2), (3, 3), (4, 4), and (5, 5)
(1, 2), (1, 3), (1, 4), and (1, 5)
(2, 1), (3, 1), (4, 1), and (5, 1)
​(2, 2), (2, 3), (5, 4), and (5, 5)​