Correct Answer: A

Rationale: The correct answer is A, cystic fibrosis. Cystic fibrosis is a genetic disorder characterized by the buildup of thick, sticky mucus in the lungs and digestive system, resulting in severe respiratory and digestive issues. Choice B, pulmonary fibrosis, involves scarring and thickening of lung tissue, not excessive mucus production. Choice C, pulmonary edema, refers to fluid accumulation in the lungs, not mucus buildup. Choice D, bronchiectasis, is a condition where the airways in the lungs are damaged and widened, leading to chronic cough and sputum production, but it does not specifically involve the thick, sticky mucus characteristic of cystic fibrosis.

Correct Answer: A

Rationale: Cardiac arrest is the correct answer. It is a sudden, unexpected loss of heart function, breathing, and consciousness, typically resulting in death if not treated immediately. Myocardial infarction (choice B) refers to a heart attack caused by a blockage in the coronary arteries. Heart failure (choice C) is a chronic condition where the heart is unable to pump blood efficiently. Atrial fibrillation (choice D) is an irregular and often rapid heart rate that can lead to complications but is not the same as cardiac arrest.

Correct Answer: A

Rationale: Anaphylaxis is the correct answer. It is a severe, potentially life-threatening allergic reaction that can lead to difficulty breathing, low blood pressure, and loss of consciousness. An asthma attack is a separate condition characterized by narrowed airways and difficulty breathing, but it is not necessarily related to an allergic reaction like anaphylaxis. Bronchospasm refers to the sudden constriction of muscles in the bronchi, leading to breathing difficulties, and is not specific to allergic reactions. Hypersensitivity is a general term for an exaggerated immune response to a substance, which may or may not manifest as severe allergic reactions like anaphylaxis.

Correct Answer: A

Rationale: Bronchodilators are medications that relax the muscles around the airways, improving airflow and making breathing easier for patients with asthma or COPD. Corticosteroids are anti-inflammatory drugs used to reduce airway inflammation, while mucolytics help in thinning and clearing mucus. Antihistamines are used to treat allergies and not specifically to improve breathing in conditions like asthma or COPD.

Correct Answer: A

Rationale: Cardiomyopathy is the correct answer. In cardiomyopathy, the heart muscle becomes weak and cannot pump blood effectively, which can lead to heart failure. Myocarditis (choice B) is inflammation of the heart muscle, not specifically causing muscle weakness. Endocarditis (choice C) is an infection of the inner lining of the heart chambers and valves. Pericarditis (choice D) is inflammation of the pericardium, the outer lining of the heart.