Answer:
B
Step-by-step explanation:
In a function the x value cannot repeat
As long as no x value repeats it is considered a function
In answer choice A the x value "1" repeats therefore table a is not a function
In answer choice B no x value repeats twice. This one might be the answer however lets check the other tables just to be safe.
In answer choice C the x value "-4" repeats multiple times therefore table C is not a function
In answer choice D the x value "1" and "2" repeat therefore table D is not a function.
Thus, the answer is B
