Determine If the Relation Illustrated Is a Function

Determine if the relation illustrated is a function. Give the domain and range of the function or relation.
-{(-2, 7) , (-1, 4) , (0, 3) , (1, 4) , (3, 12) }

A) function
B) function domain: {7, 4, 3, 12} domain: {-2, -1, 0, 1, 3}
Range: {-2, -1, 0, 1, 3} range: {7, 4, 3, 12}
C) not a function
D) not a function domain: {-2, -1, 0, 1, 3} domain: {7, 4, 3, 12}
Range: {7, 4, 3, 12} range: {-2, -1, 0, 1, 3}