The answer Is B good Luck
Diaphragm...is the muscle that helps in respiration.....there are also some other but....you said flat so diaphragm !
... termed "hypotonic," meaning less solids (or more diluted) than inside the cell. For fluid movement in/out of cells, water will diffuse (via osmosis) from the hypotonic solution to the hypertonic one, assuming a permeable barrier (i.e. cell membrane) allows it. With this case, water will flow into the cell from outside.
