Answer:

Step-by-step explanation:
In the picture.
I hope that it's a clear solution.
The points have to have the coordinate y=4 to be on the y=4 line
only the (1, 4) point matches this, so yes it is a solution, all others not and are therefore no

When 0 is in the numerator, then the whole fraction becomes equal to 0.
However if 0 is in the denominator, then it is undefined.