Question

Function problem

Answer 1

do you know if it's a function ?

Answer 2

yes, it's a function
it is not a function if you have two dots over the same x (it fails the vertical line test)

Answer 3

so the answer is either A or B

Answer 4

the graph shows "dots"
rather than a smooth line.
we can not assume we know what its values are in between the dots.
so I would pick the lists of numbers.