Correct Answer: B

Rationale: The correct answer is B because rubella can indeed damage the organ of Corti in the fetus, which is responsible for hearing. During the first trimester, when the hearing structures are forming, any damage to the organ of Corti can result in impaired hearing for the infant. Choice A is incorrect because rubella can impact the fetus, including the organs responsible for hearing. Choice C is incorrect because rubella can be harmful to the fetus at any stage of pregnancy, not just the second trimester. Choice D is incorrect because CN VIII (the vestibulocochlear nerve) is not directly affected by rubella, rather it is the organ of Corti that is damaged.

Correct Answer: C

Rationale: The correct answer is C: CN VIII. The vestibulocochlear nerve (CN VIII) is responsible for conducting nerve impulses from the organ of Corti in the inner ear to the brain. This nerve specifically carries auditory information to the brainstem and auditory cortex for processing. Choice A (CN I) is incorrect as it is the olfactory nerve responsible for smell. Choice B (CN III) is incorrect as it is the oculomotor nerve responsible for eye movement. Choice D (CN XI) is incorrect as it is the accessory nerve responsible for neck and shoulder movements.

Correct Answer: B

Rationale: The bright cherry-red coloring in a semiconscious woman found on the floor in her kitchen indicates carbon monoxide poisoning. Carbon monoxide binds to hemoglobin with a higher affinity than oxygen, leading to tissue hypoxia and the characteristic cherry-red coloration. Polycythemia would result in a purplish-red color, carotenemia in a yellow-orange hue, and uremia in a pale or yellowish complexion. Therefore, the correct answer is B, as it aligns with the clinical presentation and pathophysiology of carbon monoxide poisoning.

Correct Answer: D

Rationale: The presence of black and white dots on the tympanic membrane and ear canal wall during an otoscopic examination suggests a yeast or fungal infection. This is because yeast or fungal infections commonly present as white or black dots in the ear canal. Malignancy would typically manifest as abnormal growths or masses, not dots. Viral infections usually do not present as specific dots on the tympanic membrane. Blood in the middle ear would appear as red or pinkish fluid behind the eardrum, not as black and white dots. Therefore, the correct answer is D: Yeast or fungal infection.

Correct Answer: C

Rationale: The correct answer is C: Pull the pinna up and back before inserting the speculum. This is because pulling the pinna up and back straightens the auditory canal, allowing for easier and more accurate insertion of the speculum without causing discomfort or injury. Option A is incorrect as tilting the head forward may obstruct the view. Option B is incorrect as maintaining traction is essential for stability. Option D is incorrect as using the smallest speculum may not provide a clear view or proper insertion depth.