The correct option is C spasm in bronchial muscles
Asthma is a respiratory disorder. It is generally caused by hypersensitivity of bronchiole to foreign particles present in the air. There is an inflammation of bronchi and bronchioles. Inflammation is characterized by heat, pain, redness, and swelling. The symptoms may be coughing, difficulty in breathing etc. This breathing difficulty leads to wheezing which is a high-pitched, coarse whistling sound. Asthma is characterized by spasms (sudden, uncontrollable contraction) of smooth muscles located in bronchiole walls.
Trachea is a term for windpipe which connects the larynx (voice box) with the lungs. Tracheal infection doesn’t lead to asthma.
Lungs are vascularised (containing blood vessels) bag-like structures that provide the site for gaseous exchange. There is no bursting of lungs in asthma.
The pleural cavity is a thin fluid-filled space surrounding the lungs. There is no occurrence of bleeding in asthma.