Answer:
C
Step-by-step explanation:
It's C because the rest of the graphs that do start with 0 are not linear and if she wants the mixture to be porptional is must be straight, B is not straight meaning the only other option left to the answer is C.
A
Another name for proportional is equivalent. As you can see, option A has a straight line. This shows proportionality, therefore, "A" is the answer.
