When food is swallowed, it needs to pass through the esophagus into the stomach. The epiglottis is a flap of tissue that prevents food and liquids from entering the windpipe (trachea) and directs them to the esophagus.
If the epiglottis fails to close properly during swallowing, food may enter the trachea and cause a coughing reflex to clear the airway. This is the cause of coughing during swallowing.
Thus, the correct answer is Option (A): Epiglottis.
Match the following:

Assertion: The male ants are developed by parthenogenesis from unfertilized eggs.
Reason: The sex of offspring depends on the type of sperm that fertilizes the ovum, which is not relevant since male ants develop through haploid parthenogenesis, which does not involve fertilization.
Match the following:

Two concentric thin circular rings of radii 50 cm and 40 cm each, carry a current of 3.5 A in opposite directions. If the two rings are coplanar, the net magnetic field due to the two rings at their centre is: