Answer:
below the lungs above the ribs
Step-by-step explanation:
The diaphragm is a thin skeletal muscle that is located at the base of the chest.
This muscle contracts and flattens when one inhales, this in turn creates a vacuum that pulls air into the lungs.
The muscle relaxes when one exhales and the air is pushed out of lungs.
The diaphragm separates the abdomen from the chest.
The above process is known as breathing.
This is what causes the chest to move up and down.