I need help with this question, pls...

Greetings.

The answer is 7.

Explanation:

Function is a set of relation with domains that are not repetitive. What I'm trying to say is that in a single set, there cannot be same domain values.

For example,

(1,2) (1,3)

The relation above is not a function since the domain is repetitive (There are two 1's as domain which is not a function.)

But If it is (1,2) (2,1) (3,1) Then It's a function. Because there are no repetitive domains.

The question asks you which value would give the whole set only a relation and not a function.

As explained, 2 repetitive, same domains don't make the relation a function, but rather a relation instead.

Hope this helps! :)

Feel free to ask anything in the comment/reply if you are curious/confused with Function.