Answer:
OA. (1,6), (2, 7), (4,9), (0,5).
Explanation:
To determine whether a list of ordered pairs is a function, you need to check whether each element in the domain (the set of input values) is associated with exactly one element in the range (the set of output values).
In this case, the list OA. (1,6), (2, 7), (4,9), (0,5) is a function because each element in the domain (1, 2, 4, 0) is associated with exactly one element in the range (6, 7, 9, 5).
List OB. (2, 4), (0, 2), (2, -4), (5, 3) is not a function because the element 2 appears twice in the domain and is associated with two different elements in the range (4 and -4).
List OC. (0, 2), (2, 3), (0, -2), (4, 1) is not a function because the element 0 appears twice in the domain and is associated with two different elements in the range (2 and -2).
List OD. (1, 2), (1, -2), (3, 2), (3, 4) is not a function because the element 1 and 3 appear twice in the domain and are associated with two different elements in the range (2 and -2, and 2 and 4, respectively).
Therefore, the correct answer is OA. (1,6), (2, 7), (4,9), (0,5).