Question 1194439
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As the other tutor mentioned, you didn't post the four points. So it is currently impossible to answer this problem. But I will show the technique on how to solve problems like this. 


Let's say, for example, that we had a set of these four points
{
(1,2)
(3,4)
(5,6)
(7,8)
}
Notice that none of the x values repeat themselves. Those x values are 1,3,5,7
The x coordinates are unique without any repeats.


Now if we were to put the point (3,0) into the mix, then x = 3 does repeat itself with (3,4) and (3,0).
At this point, we do NOT have a function. 
The input x = 3 leads to multiple outputs y = 4 and y = 0 simultaneously.
A function is only possible when each input (x) leads to exactly one output (y).
This means we cannot add (3,0) and still have a function. We'd have to add some other point.


Of course, the set of four points I came up with above is purely an example. It's very unlikely it matches perfectly with the four points you were given. 


In short: If x repeats itself, then we don't have a function. So choose the answer choice where x doesn't repeat itself.
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