Answer:
C
Step-by-step explanation:
A set of pairs is a function if and only if there is only <em>one</em> y-value for each x-coordinate. In other words, the x-coordinate <em>cannot </em>repeat. If it does, then it must equal the same thing.
Let's go through each of the choices.
For A, -5 repeats twice. It simultaneously equals both 4 and -2. This cannot be true if this is a function, so A is not correct.
For B, 2 repeats twice. It equals both 6 and -6. So, this is also not a function.
For C, no digits are repeating. Thus, this is a function.
To make sure, in D ,-3 is repeating. It is both -4 and 8, so this is not a function.
So, our answer is C.
And we're done!