Answer:
(B) {(2,1),(4,3),(5,7)}
Step-by-step explanation:
If the same x value goes to 2 different y values, it is not a function
(A) {(2,3),(2,5),(4,7)} the x value 2 goes to 3 and 5
(B) {(2,1),(4,3),(5,7)}
(C) {(3,-2),(2,4),(3,6)} 3 goes to -2 and 6
(D) {(-1,4),(-1,5),(2,5)}-1 goes to 4 and 5