Step-by-step explanation:
For a relation to be a function there can't be more than one element from the range that corresponds to a single element in the domain. There can be two elements from the domain corresponding to the same element in the range in a function.
In this problem, the value 5 in the domain repeats for -1 and 1 in the domain, but there are not repeated values of the domain for only one element in the range. Therefore this relation is a function.
Answer:
A- Function