Explanation:
A relation is a function if and only if there is one value of x for different values of y.
This means that if we see repeated x-values then it's not a function. We can see this clearly in the graphs by drawing a vertical line for the values of x. Of the line crosses the graph more than once, then it's not a function.
In every graph the line crosses the graph more than once, so none of these options are functions.
Then, for a set of points we have to check the x-coordinate of each pair. If one repeats in the set, then it's not a function.
In the relation E x = -5 is repeated, so it's not a function. On the other hand, for relation D none of the x-coordinates are repeated. Therefore relation D IS a function
Answer:
Option D is a function
