Let's answer 1 and 2;
1.) From the given table, each Domain has a different pair of Range. Because of this, we can say that the table is a function. One relationship can be called a function if its Domain has a different pair of Range.
2.) From the given table, 3 out of 4 Domains has only 1 equivalent Range. Therefore, the relationship shown by the table is not a function.
To answer the rest of the relationships, one is called a function if each pair of a given set is unique. Otherwise, they are not a function.