100. Let A = {1, 2, 3, 4} and B = {0, 1, -1, 2} and several sets of ordered pairs be specified as :
I. {(1, 0), (2, 1), (3, -1), (4, 2)}
II. {(1, 0), (2, -1), (3, 2)}
III. {(4, 1), (3, 2), (2, 3), (1, 4)}
IV. {(2, 1), (3, 0), (1, - 1), (3, 1), (4, 2)}
V. {(2, 0), (1, -1), (3, 2) (4, 1)}
Which of the sets of ordered pairs are graphs of a function from A → B ?