Imagine you are trying to fit down an aisle at the local store that is filled with boxes. In order to squeeze between two stacks of boxes you need to "suck it in." Which of the following descriptions best explains why "sucking it in" isn't the best way to fit through a tight space?

While sucking it in, your diaphragm contracts and moves down causing the lung volume to increase. This causes the rib cage to move up and out, making your chest expand.

Explanation:

Fitting through a tight space is not good and may be dangerous.

A local store is filled with boxes all around and I need to try to fit in through the aisle. But in order to move through the stack of boxes I need to "suck in" through the stack of boxes.

But doing this may be considered dangerous and is harmful to the body.

When we try to suck in or pass through the stack of boxes our diaphragm contracts and moves down due to the pressure. This causes the lung volume to increase and the rib cage moves up and bulges out. By this our chest expands.

This is very dangerous and and can be fatal.

Thus the answer is

While sucking it in, your diaphragm contracts and moves down causing the lung volume to increase. This causes the rib cage to move up and out, making your chest expand.