Correct Answer: A

Rationale: The correct answer is A because in cases of anteriorly situated placenta praevia, where the placenta partially or completely covers the cervix, a classical caesarean section is indicated to prevent severe bleeding during delivery. For choice B, a posteriorly situated placenta praevia does not necessitate a classical caesarean section. Choice C, gestation of more than 32 weeks, does not specifically indicate the need for a classical caesarean section. Choice D, aesthetic purpose on maternal request, is not a valid medical indication for a classical caesarean section.

Correct Answer: A

Rationale: The correct answer is A: There is a slightly higher risk of neurologic complications. Rationale: 1. Off-pump bypass grafting involves performing surgery on a beating heart without the use of a heart-lung machine. 2. The lack of cardiopulmonary bypass during off-pump surgery can lead to reduced blood flow to the brain, increasing the risk of neurologic complications. 3. This is why the AGACNP advises Mr. Nelson about the slightly higher risk of neurologic complications associated with off-pump bypass. 4. Choice B is incorrect as long-term results actually suggest similar or better patency rates for grafts in off-pump surgery. 5. Choice C is incorrect as the statement about the incidence increasing significantly in the last 10 years is not relevant to the risks of off-pump surgery. 6. Choice D is incorrect as off-pump surgery is not considerably more expensive and the correlation with better long-term outcomes is debatable.

Correct Answer: D

Rationale: The correct answer is D: Compound presentation. This term refers to the situation where there is more than one part of the fetus on the pelvic brim at the onset of labor. This can include a hand or arm alongside the head or another body part. The other choices are incorrect because: A: Unstable lie refers to the fetus being in a transverse position. B: Fetal malpresentation indicates an abnormal presentation of the fetus, such as breech or transverse. C: Fetal malposition refers to the fetus being in a suboptimal position, like occiput posterior. Thus, the best choice is D as it specifically describes the scenario of multiple fetal parts on the pelvic brim.

Correct Answer: A

Rationale: The correct answer is A because high-volume liver resection is typically performed in individuals with significantly compromised hepatic function to ensure adequate liver remnant. Removing 50 to 75% of the liver in a patient with metastatic colon cancer may be necessary for tumor clearance but carries risks due to potential impairment of liver function postoperatively. Choices B and C provide inaccurate information regarding the timeline and extent of liver regeneration following resection. Choice D is incorrect as removing up to 95% of the liver would lead to severe consequences, such as liver failure. Hence, option A is the most appropriate advice given the patient's situation.

Correct Answer: A

Rationale: The correct answer is A (Low ACTH and low cortisol) because in patients with an adrenal tumor causing Cushing's syndrome, the tumor autonomously produces cortisol, leading to suppression of ACTH secretion from the pituitary. This results in low ACTH levels and high cortisol levels. Choices B, C, and D are incorrect because they do not reflect the characteristic hormone levels seen in patients with an adrenal tumor causing Cushing's syndrome.