Answer:
B represents a function.
Step-by-step explanation:
Recall these characteristics of a "function:"
Only one y-value can be associated with each x-value.
Thus, A could not represent a function because there are two points with x = 1 and two different y-values: (1, 1) and (1, -2).
B represents a function because for each input (x-value) there is one and only one y-value associated.
C not a function: (2, 3) and (2, -3) have two different y-values associated with one x-value (2).
D not a function: (-3, 4) and (-3, -4) (see A and C, above)
