Please help with this

Answer:
A). Not a function
B). Function
C). Function
Step-by-step explanation:
A). Since x = 3 produces y = 4 and y = 8 , the relation ( 3,4 ) , ( 3,8 ) , ( 5,7 ) is not a function.
B). Since there is one value of y for every value of x in ( 3,4 ) , ( 3,4 ) , ( 1 ,− 2 ) , this relation is a function.
C). Since there is one value of y for every value of x in ( 2,3 ) , ( 1,3 ) , ( − 5,3 ) , this relation is a function.