Gases have no fixed volume or shape. So eliminate B.
Now we have A and C so
When it said that for A that gas has a fixed volume but takes the shape of a container, it’s true that it does because it’s making both volume and shape to form in the container.
It’s either those two but either wise good luck. If this is a more than one answer choice that’s good or if it isn’t good luck to that because it’s either A or C
