Help me with this question plz! The equation t=0.07c represents the tax t, based on the cost c, of an item. Which part of the equation represents the constant of proportionality?
A: t
B: 0.07
C: c
D: 7
Help fast!! 15 points!!
A: t
B: 0.07
C: c
D: 7
Help fast!! 15 points!!