Determine Whether the Relation Represents a Function

Determine whether the relation represents a function. If it is a function, state the domain and range.
-{(-2, 7) , (1, 3) , (3, 0) , (8, -1) }

A) function
B) not a function
C) function domain: {7, 3, 0, -1} domain: {-2, 1, 3, 8}
Range: {-2, 1, 3, 8} range: {7, 3, 0, -1}