Correct Answer: B

Rationale: The correct answer is B: A dark retinal background. This is because individuals of African descent typically have a higher concentration of melanin in their eyes, resulting in a darker retinal background. This can affect the appearance of the fundus during eye examinations. Incorrect choices: A: Increased night vision - Night vision is not directly influenced by melanin levels in the eyes and is more related to the function of rods and cones in the retina. C: Increased photosensitivity - Melanin provides some protection against UV light, so individuals with darker retinas may have lower photosensitivity. D: Narrowed palpebral fissures - Palpebral fissures refer to the opening between the eyelids and are not typically influenced by melanin levels in the eyes.

Correct Answer: A

Rationale: The correct answer is A. Referring the patient to an ophthalmologist or optometrist is the appropriate action because the patient's inability to read the 20/100 line on the Snellen chart suggests significant visual impairment that requires professional evaluation. Options B and C are incorrect as they do not address the underlying cause of the vision issue. Option B focuses on a different method of assessment and does not provide a solution for the patient's visual acuity problem. Option C assumes the patient's vision issue can be corrected by reading glasses, which may not be the case for a 20/100 visual acuity. Option D is also incorrect as it only adjusts the testing distance and does not address the need for a comprehensive evaluation by an eye care specialist.

Correct Answer: A

Rationale: The correct answer is A: acquired immunodeficiency syndrome (AIDS). The dark red confluent macule on the hard palate is known as Kaposi's sarcoma, a common manifestation of AIDS. This lesion is caused by Human Herpesvirus 8 and is often seen in patients with compromised immune systems. Measles (B) typically presents with a rash, not a dark red macule. Leukemia (C) does not typically manifest as a dark red macule in the mouth. Carcinoma (D) refers to cancer and would present differently than Kaposi's sarcoma. In summary, the presence of a dark red confluent macule on the hard palate in a patient with a history of intravenous drug abuse is highly suggestive of AIDS, specifically Kaposi's sarcoma.

Correct Answer: B

Rationale: The correct answer is B: A dark retinal background. This is because individuals of African descent typically have a higher concentration of melanin in their eyes, resulting in a darker retinal background. This can affect the appearance of the fundus during eye examinations. Incorrect choices: A: Increased night vision - Night vision is not directly influenced by melanin levels in the eyes and is more related to the function of rods and cones in the retina. C: Increased photosensitivity - Melanin provides some protection against UV light, so individuals with darker retinas may have lower photosensitivity. D: Narrowed palpebral fissures - Palpebral fissures refer to the opening between the eyelids and are not typically influenced by melanin levels in the eyes.

Correct Answer: D

Rationale: The correct answer is D because a bruit in a 3-year-old child, especially over the temporal area, is not a normal finding and could indicate a serious underlying issue such as an arteriovenous malformation or other vascular abnormality. Stopping the examination and notifying the physician is crucial for further evaluation and management. A: Continuing the examination is not appropriate as the bruit should prompt further investigation. B: Checking again in 1 hour is unnecessary delay in addressing a potentially serious issue. C: Notifying the parents alone without medical intervention may delay necessary evaluation and treatment.