Answer:
option (a) is correct
Step-by-step explanation:
A function is a relation in which each possible input value leads to exactly one output value.
is a function of if each has a different .
13 only has one corresponding y value (-13)
-13 only has one corresponding y value (12)
14 only has one corresponding y value (-14)
-14 only has one corresponding y value (14)
Here, each x has different y.
Therefore, option (a) is correct
