Which of the following represents an exponential relationship?
A
(1,5),(2,10),(3,15)(1,5),(2,10),(3,15)
B
(2,9),(3,27),(4,81)(2,9),(3,27),(4,81)
C
(2,4),(3,9),(4,16)(2,4),(3,9),(4,16)
D
(5,15),(6,18),(7,21)