Correct Answer: B

Rationale: The correct answer is B: reduce serum sodium concentration by infusing a 0.45% sodium chloride solution. In hyponatremic hyperosmolality, the primary goal is to correct the low serum sodium levels. A 0.45% sodium chloride solution is hypotonic, which helps to slowly correct the serum sodium concentration without causing rapid shifts in osmolality. Infusing a hypotonic solution will gradually increase the serum sodium levels, addressing the underlying issue. Choices A, C, and D are incorrect because they do not directly address the low serum sodium levels, which is essential in treating hyponatremic hyperosmolality. Infusing a 5% dextrose in 0.2% sodium chloride solution (Choice A) or a 5% dextrose in water solution (Choice D) would not correct the low sodium levels. Replenishing volume with a 0.9% sodium chloride solution (Choice C) would not directly

Correct Answer: B

Rationale: The correct answer is B: Placental bed. Malaria parasites hide in the placental bed during pregnancy to avoid detection by the immune system. This location provides a safe haven for the parasites to survive and replicate without being cleared by the mother's immune response. The placental bed offers a rich blood supply and a favorable environment for the parasites to thrive. Incorrect choices: A: Bone marrow - Malaria parasites do not typically hide in the bone marrow during pregnancy. C: Fetal circulation - Malaria parasites do not hide in the fetal circulation; they primarily reside in the placental bed. D: Uterine muscle - Malaria parasites do not hide in the uterine muscle; the placental bed is the main site of sequestration during pregnancy.

Correct Answer: A

Rationale: The correct answer is A because congenital abnormalities and chorioangioma can lead to increased amniotic fluid accumulation, causing polyhydramnios. Congenital abnormalities can affect fetal swallowing and urine production, leading to fluid buildup. Chorioangioma is a vascular tumor in the placenta that can disrupt normal fluid dynamics. Choice B is incorrect as severe fetal hypoxia and multiple pregnancy are more likely to cause oligohydramnios, not polyhydramnios. Choice C is incorrect as uncontrolled diabetes mellitus and anemia are associated with macrosomia and not polyhydramnios. Choice D is incorrect because Rhesus D isoimmunisation and postdatism are not typically linked to polyhydramnios.

Correct Answer: B

Rationale: Breech presentation refers to the bottom or feet-first position of the baby in the uterus. This is the correct answer (B) because it accurately defines breech presentation. Choice A (head-first presentation) is incorrect as it describes the typical vertex presentation. Choices C (oblique lie) and D (transverse lie) are also incorrect as they refer to other abnormal fetal positions that are different from breech presentation.

Correct Answer: C

Rationale: The correct answer is C because secondary post-partum hemorrhage can occur up to 6 weeks (46 days) after delivery, typically due to delayed complications like retained placental fragments or infection. Choice A is incorrect because most secondary post-partum hemorrhage occurs after the first week. Choice B is incorrect as it describes primary post-partum hemorrhage, which occurs within 24 hours of delivery. Choice D is incorrect since lochia serosa is a normal discharge present in the early post-partum period and is not specific to diagnosing secondary post-partum hemorrhage.