Correct Answer: B

Rationale: The correct answer is B: Ammonia. Ammonia is a primary chemical mediator of hepatic encephalopathy. In patients with chronic liver disease, the liver's ability to detoxify ammonia is compromised, leading to its accumulation in the bloodstream and subsequent neurotoxic effects causing encephalopathy. Gamma-aminobutyric acid (GABA), false neurotransmitters, and serotonin are all implicated in the pathophysiology of hepatic encephalopathy. GABA is involved in neurotransmission, false neurotransmitters are substances that disrupt normal neurotransmission, and serotonin levels are altered in hepatic encephalopathy.

Correct Answer: A

Rationale: The correct answer is A: They are always of the same sex. This is because monozygotic twins, also known as identical twins, develop from a single fertilized egg that splits into two embryos. As a result, they share the same genetic material and are always of the same sex. Choice B is incorrect because fingerprint patterns are not determined by genetics and can vary even between identical twins. Choice C is incorrect because monozygotic twins share the same blood type since they have the same genetic makeup. Choice D is incorrect as superfetation, the occurrence of multiple pregnancies in the same uterus but from different ovulations, is extremely rare and not a common finding in monozygotic twins.

Correct Answer: B

Rationale: The correct answer is B: A surgical procedure in which the cartilage of the pubic symphysis is divided. Pubiotomy involves cutting the pubic symphysis cartilage to widen the pelvic outlet during difficult childbirth. This procedure helps facilitate labor by increasing the pelvic diameter. Choices A, C, and D are incorrect because they do not accurately describe pubiotomy. Choice A refers to accessing the lower uterine segment, choice C involves ligating pubic bones for cancer, and choice D pertains to perineal tissue dissection during labor, which are unrelated to pubiotomy.

Correct Answer: A

Rationale: The correct answer is A: Fetal macrosomia. Prolonged pregnancy increases the risk of fetal macrosomia due to continued fetal growth beyond the normal term. This can lead to complications during delivery, such as shoulder dystocia and birth injuries. Placental dysfunction and cesarean section are possible outcomes of prolonged pregnancy but are not directly associated with fetal risks in this context. Shoulder dystocia is a potential complication of fetal macrosomia but is not a direct fetal risk of prolonged pregnancy.

Correct Answer: A

Rationale: The correct answer is A because Bishop's score assesses the readiness of the cervix for labor by evaluating descent (station of the fetal head), presentation (fetal position), and cervical dilatation, which are key indicators of cervical ripening and effacement. Descent shows the progress of the fetus through the birth canal, presentation indicates the fetal position for delivery, and cervical dilatation reflects the opening of the cervix for labor. Choices B, C, and D are incorrect as they do not encompass all the essential components of Bishop's score, which focuses on descent, presentation, and cervical dilatation.