Answer: D ( 7,3 7,6 7,9 7,12 7,15)
Explanation:
A- (-4, 0, 7, 3, -7) There are no repeating domains, therefore, this is a function
B- (1, 3, 5, 7, 9) The domain does not repeat, therefore this is a function
C- (4, 8, 12, 16, 20) The domain does not repeat, therefore this is a function
D- (7, 7, 7, 7, 7) The entire domain repeats, therefore this cannot be a function
Correct answer is D ( 7,3 7,6 7,9 7,12 7,15)