What does the following mapping diagram represent?
(A picture is shown with two ovals each with the numbers 1 through 5 vertically displayed in descending order. Arrows are pointing between the two ovals. One arrow is from 1 in the first oval to 1 in the second, and there's another arrow that points from 1 in the first to 2 in the second. Each of the other arrows point from each number in the first oval to the same number in the second.)
A. A relation that is not a function
B. A function that is not a relation
C. A relation that is a function
D. Neither a relation nor a function