Correct Answer: C

Rationale: The correct answer is C: Oligohydramnios. Shoulder presentation occurs when the baby presents shoulder-first rather than head-first during birth. Oligohydramnios, a condition characterized by low levels of amniotic fluid, can lead to decreased uterine space, increasing the chances of abnormal fetal positioning. Macerated fetus (A) is associated with fetal decomposition, not shoulder presentation. Postdates pregnancy (B) is linked to increased risk of macrosomia but not shoulder presentation. Placenta abruption (D) is a separation of the placenta from the uterus, not a direct cause of shoulder presentation.

Correct Answer: C

Rationale: The correct answer is C: Depression. Psychosis during puerperium commonly manifests as postpartum depression, characterized by feelings of extreme sadness, anxiety, and fatigue. This is due to hormonal changes and stress associated with childbirth. Mania (choice A) and bipolar disorder (choice B) are less common during this period. Infection (choice D) is not a typical manifestation of psychosis during puerperium. Overall, postpartum depression is the most prevalent and well-documented form of psychosis in the postpartum period.

Correct Answer: B

Rationale: The correct answer is B: Oligohydramnios. Oligohydramnios leads to reduced volume of amniotic fluid, which can result in poor fetal movements and inadequate cushioning for the fetus. This can increase the likelihood of abnormal fetal positions like shoulder presentation. Other choices are incorrect because: A: A sub-septate uterus is a structural uterine abnormality and not directly related to shoulder presentation. C: Prematurity may lead to preterm labor but is not specifically associated with shoulder presentation. D: Multiple pregnancy can increase the risk of malpresentation but is not a direct maternal cause of shoulder presentation.

Correct Answer: D

Rationale: The correct answer is D: Elective lymph node dissection. This is because elective lymph node dissection helps to remove potentially cancerous lymph nodes, aiding in staging and ensuring complete tumor removal, thus improving the chances of curative surgery. En bloc resection (A) is important but may not always be feasible in fixed tumors. Adjuvant therapies (B) are used after surgery, not as the primary approach. Neoadjuvant therapies (C) are given before surgery to shrink tumors, not specifically for fixed tumors.

Correct Answer: A

Rationale: The correct answer is A: Wernicke's encephalopathy. Hyperemesis gravidarum is severe nausea and vomiting during pregnancy. Wernicke's encephalopathy is a neurological complication due to thiamine deficiency, which can occur in severe cases of vomiting, leading to impaired brain function. Sheehan's syndrome is a complication of postpartum pituitary necrosis. Maurice encephalitis is a fictional term not related to this context. Antepartum bleeding is not a typical complication of hyperemesis gravidarum. Therefore, the correct answer is A due to the potential neurological impact of severe vomiting on thiamine levels.