Correct Answer: A

Rationale: The correct answer is A because at 7 months, infants typically have developed the ability to localize sounds. When clapping hands, the expected response is for the infant to turn their head towards the sound source, indicating their ability to detect and localize the sound. This behavior reflects the normal auditory development at this age. Choice B is incorrect because by 7 months, infants should show some response to noise, such as turning their head or showing some interest. Choice C is incorrect as the startle and acoustic blink reflex typically occur in response to sudden loud noises, but at 7 months, the infant should also be able to localize the source of the sound. Choice D is incorrect as stopping all movement and appearing to listen is not a typical response expected from a 7-month-old when hearing a sound. Infants at this age are more likely to actively turn towards the sound source to investigate.

Correct Answer: C

Rationale: The correct answer is C because pain in the ear when people speak loudly can be a sign of a middle ear infection. This is due to increased pressure in the middle ear caused by inflammation or fluid buildup. Recruitment (B) is a phenomenon related to hearing loss, not ear pain. Cerumen impaction (D) would not typically cause pain in response to loud sounds. It is not normal for a person of that age to experience ear pain when people speak loudly (A).

Correct Answer: B

Rationale: The correct answer is B: It is the most common type of glaucoma. Open-angle glaucoma is indeed the most common type, accounting for about 90% of all glaucoma cases. In open-angle glaucoma, the drainage angle of the eye remains open, but the trabecular meshwork becomes blocked over time. This leads to increased intraocular pressure, which can damage the optic nerve and result in vision loss. A, C, and D are incorrect: A: The symptoms mentioned (sensitivity to light, nausea, halos around lights) are more commonly associated with acute angle-closure glaucoma, not open-angle glaucoma. C: Immediate treatment is not necessarily needed for open-angle glaucoma as it progresses slowly, and treatment can vary based on the severity of the condition. D: Vision loss in open-angle glaucoma typically starts with the loss of peripheral vision, not central vision.

Correct Answer: B

Rationale: The correct answer is B: This is a bifid uvula, which is a common occurrence in some Aboriginal groups. 1. A bifid uvula is a condition where the uvula is split or divided, which is a common variation seen in some Aboriginal populations. 2. Cleft palate is a different condition involving a gap in the roof of the mouth, not specifically related to Aboriginal people. 3. Uvular injury is not a common cause of a split uvula in children, so reporting to authorities is unnecessary. 4. Torus palatinus is a bony growth on the roof of the mouth and not related to a split uvula or specific to Aboriginal populations.

Correct Answer: D

Rationale: The correct answer is D: trichotillomania, which may be caused by her child habitually twirling her hair in an absent-minded way. Trichotillomania is a psychological disorder where individuals have an irresistible urge to pull out their hair. In this case, the broken-off, stublike hair and irregularly shaped patches on the child's head are indicative of hair pulling rather than a medical condition like folliculitis (choice A), traumatic alopecia (choice B), or tinea capitis (choice C). The child's hair being kept very short does not align with the characteristic of these conditions, making trichotillomania the most likely explanation.