Answer:
option 3. (4, -2)
Explanation:
For a relation to be a function there should be exactly one output value for a given input.
In the given relation :-
4 has 2 outputs, -2 and 2, so if we remove the pair (4, -2) 4 will have only one output value ,i. e., 2. And hence the relation will be a function.
So the answer is option 3. (4, -2)