Correct Answer: C

Rationale: The correct answer is C because establishing an intravenous line is essential for immediate access to administer fluids, medications, and blood products during the emergency cesarean section. This step ensures that the patient's vital signs can be supported, and any emergent interventions can be readily delivered. A: While informed consent is important, in an emergency situation, the priority is to ensure the patient's immediate medical needs are met. B: Inserting a Foley's catheter may be necessary during the procedure, but it is not the most critical assessment prior to the cesarean section. D: Shaving the perineal area is not a priority in an emergency situation and may be done during the preparation for surgery.

Correct Answer: D

Rationale: The correct answer is D because deep transverse arrest refers to a situation where the fetal head fails to rotate and descend in the pelvis due to the occiput and sinciput being at the same level. This leads to a prolonged labor. Choice A is incorrect because flexion can be inadequate in deep transverse arrest. Choice B is incorrect because it is not solely caused by uterine contractions but rather fetal malposition. Choice C is incorrect because a well-curved sacrum is not a defining factor in deep transverse arrest.

Correct Answer: A

Rationale: Rationale for choice A: Calcium channel antagonists are the treatment of choice for achalasia as they help relax the lower esophageal sphincter, improving swallowing. This is a non-invasive option that can provide symptom relief for many patients. Summary for other choices: B: Intrasphincter botulinum injection is a temporary solution and not considered the treatment of choice. C: Pneumatic dilation is another option for achalasia but is typically used if calcium channel antagonists are ineffective. D: Myotomy and partial fundoplication is a more invasive surgical option and usually considered if other treatments fail.

Correct Answer: B

Rationale: The correct answer is B: Magnesium sulphate. It is the drug of choice for managing eclampsia due to its ability to prevent and control seizures. Magnesium sulfate acts as a central nervous system depressant and smooth muscle relaxant, helping to prevent further seizures. Phenobarbitone (A) is not the first-line treatment for eclampsia. Calcium gluconate (C) is used to counteract calcium channel blocker toxicity, not for eclampsia. Sodium bicarbonate (D) is used to treat metabolic acidosis, not eclampsia.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Fetal macrosomia, malpresentation, and pelvic abnormalities are all known causes of obstructed labor. Fetal macrosomia refers to a large baby, which can lead to difficulty in passing through the birth canal. Malpresentation occurs when the baby is not positioned optimally for delivery, such as breech or transverse positions. Pelvic abnormalities, such as a contracted pelvis, can impede the baby's passage during labor. Therefore, selecting option D is appropriate as it encompasses all the major causes of obstructed labor. Choices A, B, and C are not individually comprehensive enough to cover all potential causes of obstructed labor.