Answer:
Choice C is correct, r is not a set of ordered pairs
Step-by-step explanation:
A relation between sets of data is a collection of ordered pairs which contain one object from each set. If the element x is from the first set and its corresponding object y from the second set, then the objects are said to be related if the ordered pair (x,y) is in the relation.
X comprises of the domain while Y makes up the range.
Therefore, r is not a relation since it is not a set of ordered pairs.