Answer:
B
Step-by-step explanation:
A function can never have a 'x' with two values.
If you say f(x) = a, then there is only one number 'a' which satisfy. If however, you say f(x) = a & f(x) = b, then it's not a function, since there are two values of f(x).
Following this,
A: x = 3 has two f(x) = 2 & 1, so it's not a function
Similarly you can check for all.
There is only one table which x has a unique value.
Correct B
Note that, f(x) = a & f(x) = b, doesnt represent a function. If it is, then a = b is must.
Also, a function is possible only when it satisfies this. But
f(x) = a, f(y) = a, f(z) = a is possible.
