Correct Answer: C

Rationale: The correct answer is C: Majority are classified as secondary face presentation. In face presentation, the fetal head is hyperextended, presenting the face to the birth canal. Primary face presentation is rare. The bi-parietal diameter is not the presenting diameter in face presentation, as it is in vertex presentation. Locating the anterior fontanelle is not diagnostic of face presentation, as the fontanelles can be difficult to palpate during labor. Therefore, the correct statement is that the majority of face presentations are classified as secondary face presentation.

Correct Answer: B

Rationale: The correct answer is B: Myelomeningocele. McEwen sign refers to the characteristic scalloping of the frontal bones due to pressure from the expanding brain in individuals with myelomeningocele. This sign is specific to myelomeningocele and is not associated with hydrocephalus (A), microcephaly (C), or encephalocele (D), which have different clinical manifestations and imaging findings. Myelomeningocele is a neural tube defect where the spinal cord and its coverings protrude through an opening in the spine, leading to neurological deficits and associated signs like McEwen sign.

Correct Answer: C

Rationale: The correct answer is C: Majority are classified as secondary face presentation. In face presentation, the fetal head is hyperextended, presenting the face to the birth canal. Primary face presentation is rare. The bi-parietal diameter is not the presenting diameter in face presentation, as it is in vertex presentation. Locating the anterior fontanelle is not diagnostic of face presentation, as the fontanelles can be difficult to palpate during labor. Therefore, the correct statement is that the majority of face presentations are classified as secondary face presentation.

Correct Answer: D

Rationale: The correct answer is D because exchange transfusion aims to control hemolysis by removing the damaged red blood cells and replacing them with healthy ones, thus restoring hemoglobin levels. This procedure does not cure haemolysis or hypoxia entirely, nor does it stabilize the immune system or liver functions. It specifically targets controlling hemolysis and restoring hemoglobin levels to improve the patient's condition.

Correct Answer: A

Rationale: The presenting diameter in brow presentation is Submentobregmatic (choice A) because it refers to the distance from the submentum (chin) to the bregma (anterior fontanelle). This is the appropriate measurement for the brow presentation as the brow is the prominent part between the forehead and the chin. Choice B (Suboccipitofrontal) is incorrect because it refers to the distance from the subocciput to the frontal bone, which is not relevant to brow presentation. Choice C (Occipitalfrontal) is incorrect because it describes the distance from the occiput to the frontal bone, which again is not specific to brow presentation. Choice D (Mentovertical) is incorrect as it denotes the distance from the chin to the vertex, which is not the relevant measurement for brow presentation.