Correct Answer: A

Rationale: Anaphylaxis is the correct answer. It is a severe allergic reaction that can result in difficulty breathing, a drop in blood pressure, and even anaphylactic shock if not treated promptly. Choice B, allergic rhinitis, is characterized by symptoms such as a runny or stuffy nose, sneezing, and itching. Choice C, bronchospasm, refers to the sudden constriction of the muscles in the walls of the bronchioles, leading to breathing difficulties. Choice D, asthma attack, involves the inflammation and narrowing of the airways, resulting in symptoms like wheezing, coughing, and chest tightness.

Correct Answer: A

Rationale: The correct answer is the Pulmonary valve. The Pulmonary valve prevents backflow of blood into the right ventricle from the pulmonary artery after it has been ejected. The Aortic valve (choice B) prevents backflow from the aorta into the left ventricle. The Tricuspid valve (choice C) prevents backflow of blood into the right atrium from the right ventricle. The Mitral valve (choice D) prevents backflow from the left ventricle into the left atrium.

Correct Answer: A

Rationale: Emphysema is the correct answer. It is a chronic lung condition characterized by the permanent enlargement and damage of the alveoli, leading to shortness of breath and impaired oxygen exchange. Bronchitis is the inflammation of the bronchial tubes, not specifically related to alveolar damage. Atelectasis is the collapse of lung tissue, not enlargement. Pulmonary fibrosis involves scarring and thickening of lung tissue, different from the alveolar damage seen in emphysema.

Correct Answer: A

Rationale: The correct answer is an echocardiogram. This test utilizes sound waves to generate images of the heart, enabling doctors to evaluate both the function and structure of the heart. Choice B, MRI, uses magnetic fields and radio waves to produce detailed images of the body's organs and structures, not specifically focused on the heart. Choice C, CT scan, employs X-rays to create detailed cross-sectional images of the body, not primarily for the heart. Choice D, X-ray, uses electromagnetic radiation to produce images of internal structures, but it does not provide the detailed pictures of the heart's function that an echocardiogram does.

Correct Answer: D

Rationale: The correct answer is D, Hypokalemia. Muscle cramps are a common symptom of hypokalemia, an electrolyte imbalance characterized by low potassium levels. Furosemide, a loop diuretic like Lasix, can lead to potassium loss in the body, contributing to hypokalemia. Choice A, Hyperkalemia, is incorrect as it refers to high potassium levels. Choice B, Hyponatremia, is incorrect as it pertains to low sodium levels. Choice C, Hypocalcemia, is incorrect as it relates to low calcium levels, not typically associated with muscle cramps in the context of furosemide use.