Answer:
Epiglottis
Explanation:
The epiglottis is a leaf like structure tat rests above the voice box/larynx and its main function is to seal off the windpipe during eating, so that food is not accidentally inhaled down the wind pipe. When water goes down the wrong pipe, it goes down the windpipe instead of the oesophagus resulting in water going to your lungs which causes the coughing as a protective reflex to clear the windpipe
