Is the amount of profit proportional to the number of fire pits sold?

Proportional is
if you have
y=number of pits
x=profit

then
y1/x1=y2/x2
y1 and x1 are first number of pits and profit
y2 and x2 and second number of pits and profit

so

given
3 pits and 80 then
5 pits and 200
12 pits and 620
3/80=5/200=12/620
true?
3/80=1/40=3/155
use caltulator
0.0375=0.025=0.019
these are obiously not equal
so the answer is no, so either c or d

hmm
c means that the slope (or the values we calculated) wer less than original
0.0375>0.025>0.019
true

d. this is also true since they are not proportional

not sure, it is either c or d, I would go with d

That they are numbers and related to each other.