Correct Answer: A

Rationale: The patient is presenting with chest pain that worsens with exertion and improves with rest, which is characteristic of stable angina. Additionally, ST-segment depression on ECG is a common finding in patients with stable angina. Stable angina is typically caused by coronary artery disease, which leads to partial obstruction of the coronary arteries resulting in inadequate blood flow to the heart muscle during periods of increased demand (such as exertion). The chest pain is usually predictable and reproducible, occurring with similar intensity and duration during episodes of exertion. Rest or nitroglycerin can help relieve the symptoms by increasing coronary blood flow. It is important to differentiate stable angina from unstable angina and acute myocardial infarction, which have different management and prognostic implications.

Correct Answer: B

Rationale: Streptococcus pneumoniae is the most common causative organism of bacterial pneumonia in adults. It is responsible for the majority of community-acquired pneumonia cases. Streptococcus pneumoniae is a gram-positive bacteria and is known to cause typical pneumonia characterized by sudden onset of high fever, productive cough with blood-tinged or rust-colored sputum, chest pain, and consolidation on chest imaging. Other organisms like Legionella pneumophila (choice A), Mycoplasma pneumoniae (choice C), and Haemophilus influenzae (choice D) can also cause pneumonia, but Streptococcus pneumoniae is the most likely culprit based on the patient's test results.

Correct Answer: A

Rationale: In primary care nursing, typically, one nurse is designated to have 24-hour responsibility for care planning and coordination for each patient. This helps ensure continuity of care and accountability. By having one nurse overseeing all aspects of the patient's care, it allows for a more personalized and coordinated approach that puts the patient at the center of the care structure. Having one primary care nurse also promotes better communication, efficiency, and consistency in managing the patient's health and well-being.

Correct Answer: B

Rationale: The cardiovascular disorder most likely responsible for the symptoms described is a pericardial effusion. A pericardial effusion is an accumulation of fluid within the pericardial space surrounding the heart. When a large pericardial effusion is present, it can lead to compression of the heart chambers, resulting in symptoms such as chest pain and dyspnea.

Correct Answer: B

Rationale: Dental caries, commonly known as tooth decay, is characterized by the irreversible demineralization of the enamel and dentin due to acids produced by bacterial activity. This process leads to cavitation and destruction of the tooth structure, ultimately resulting in the formation of a cavity. Gingivitis is inflammation of the gums, periodontitis is inflammation and infection of the supporting structures of the teeth (gums, bone, and ligaments), and a dental abscess is a collection of pus in the tissues surrounding the tooth, none of which are specifically related to the irreversible demineralization of enamel and dentin seen in dental caries.