suggest one reason to explain why DiagramB is not an accurate model to show the action of breathing?

Question

diagramB is a glass jar with a rubber sheet tightly fixed to the bottom opening of the glass jar. it also has a tube fixed into the cork at the top opening of the glass jar. it has two balloons fixed to the tube. the tube and the balloons are acting as the lungs while the rubber sheet is acting as the diapragm.

Answer 1

It sounds like there is no attempt made to remove the air that is in the jar and outside the balloons. In the chest, the lungs fill all the available space; there is little or no air outside the lungs. With air in that space, the jar is a model of someone with a pneumothorax.
Also, the chest is able to expand to accommodate the increased volume of the lungs when filled, whereas the jar doesn't expand.