The correct option is B Both the assertion and reason are true but the reason is not the correct explanation for the assertion
Pharynx is the common passage for food and air which further opens into two openings. The dorsal opening is the gullet which is the part of the digestive tract and opens into the oesophagus. The ventral pore is known as the glottis which is the part of the respiratory tract and opens into the larynx. Over the glottis, there is a flat leaf-shaped cartilage named epiglottis. At the time of swallowing of food, the epiglottis covers the glottis and prevents the entry of food into the respiratory tract. So, the breathing stops due to this at the time of swallowing.