Answer:
None of the relation is a function
Explanation:
A function is a process or a relation that associates each element x of a set X to a single element y of another set Y.
one x - one y
Look at the picture.
A. For x =7 we have infinity values of y.
B. For x = 0 we have two values of y: -2 and 2.
C. For x = 1 we have two values of y: -2 and 1