Answer:
Option A:
Yes, it is proportional because it has a constant rate of change.
Step-by-step explanation:
One trick you can use to easily tell a proportional graph is that it follows a straight line. It does not matter whether the line slopes downwards or upwards. The fact that it is straight and not cured at any point, should hint you that the graph is proportional.
Proportional graphs have a constant rate of change. The value of the slope calculated when using any two (x, y) coordinates are the same for any point along the line.