Which graph shows a constant of proportionality of 4? Choose the correct answer.
A. x=1 y=4, x=3 y=12
B. x=1 y=2, x=3 y=6
C. x=1 y=6, x=2 y=12
D. x=1 y=8, x=2 y=16
A. x=1 y=4, x=3 y=12
B. x=1 y=2, x=3 y=6
C. x=1 y=6, x=2 y=12
D. x=1 y=8, x=2 y=16