I think its A but I'm not sure.
The epiglottis covers the larynx to prevent food from entering the lungs.
Endoplasmic Recticulum:
<span>a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis</span>
Elements are pure substances made up of atoms
Mediastinal shift occurs in Tension pneumothorax. A tension pneumothorax makes the lung to collapse and the heart, the trachea and the great vessels, to shift toward the unaffected side of the chest. When air moves out from a laceration in the lung and goes in the pleural space or infiltrate the pleural space over a wound in the chest wall the shift happens.
