Correct Answer: A

Rationale: Pneumoconiosis is the correct answer. It is a lung disease caused by inhaling certain types of dust, commonly in a workplace setting, resulting in lung damage. Asbestosis (choice B) is a specific type of pneumoconiosis caused by asbestos fibers. Silicosis (choice C) is another type of pneumoconiosis caused by inhaling crystalline silica dust. Anthracosis (choice D) is a condition characterized by the accumulation of coal dust particles in the lungs, not necessarily resulting in lung damage.

Correct Answer: A

Rationale: Valve replacement is the correct answer because it specifically involves surgically replacing a damaged or diseased heart valve with a prosthetic valve to address narrowing or blockage, thereby improving blood flow and heart function. Angioplasty (choice B) is a procedure to widen narrowed or obstructed arteries, typically using a balloon catheter. Stent placement (choice C) involves inserting a mesh tube to support a weakened artery. Coronary bypass surgery (choice D) is a procedure to create new routes for blood flow to the heart muscle by bypassing blocked arteries.

Correct Answer: A

Rationale: The correct answer is A: Arrhythmia. Arrhythmia is a broad term that refers to any irregularity in the heart's rhythm, which can manifest as a heartbeat that is too fast (tachycardia), too slow (bradycardia), or irregular. Choice B, Bradycardia, specifically denotes a slow heart rate, while choice C, Tachycardia, refers to a fast heart rate. Choice D, Conductivity, is not the correct term to describe an abnormal heartbeat characterized by speed irregularities.

Correct Answer: B

Rationale: The correct answer is B: Approximately 70 mL of blood per beat. The stroke volume of the heart is typically around 70 mL, indicating the volume of blood ejected from the left ventricle with each contraction. Choices A, C, and D are incorrect as they do not represent the standard approximate stroke volume of the heart, which is around 70 mL per beat.

Correct Answer: A

Rationale: An INR of 5.2 is elevated, indicating an increased risk of bleeding. Administering vitamin K can help reverse the effects of warfarin, which is the most appropriate action in this situation. Holding the next dose of warfarin is not enough to address the high INR, and increasing the dose would further elevate the INR level. Monitoring the INR closely is important, but in this case, immediate action is needed to counteract the anticoagulant effects of warfarin.