Correct Answer: A

Rationale: Mifepristone (RU-486) functions by inhibiting the action of progesterone, a hormone crucial for maintaining pregnancy. By blocking progesterone, mifepristone disrupts the uterine environment necessary for pregnancy continuation, ultimately leading to termination. Choice B is incorrect because mifepristone does not increase estrogen levels; instead, it acts on progesterone. Choice C is incorrect as mifepristone's mechanism does not involve altering the uterine lining to prevent implantation. Choice D is incorrect because mifepristone does not directly stimulate uterine contractions; its primary action is through progesterone inhibition.

Correct Answer: B

Rationale: The correct recommendation for pain at the injection site after an influenza vaccination is Acetaminophen. Acetaminophen is a suitable choice for managing mild to moderate pain and fever commonly associated with vaccinations. Choice A, ASA (aspirin), is not recommended due to the risk of Reye's syndrome in children and teenagers following viral illnesses. Choice C, Meperidine (Demerol), is a potent opioid analgesic and is not typically indicated for mild pain relief. Choice D, heat application, is not the standard recommendation for pain at an injection site and may not provide adequate relief.

Correct Answer: D

Rationale: The correct answer is D, Cystitis. Cystitis specifically refers to the inflammation of the bladder lining. Choice A, Incontinence, refers to the loss of bladder control and is not related to inflammation. Choice B, Pyelonephritis, is the inflammation of the kidney and renal pelvis, not the bladder lining. Choice C, Urinary calculi, refers to the formation of stones in the urinary tract and is not related to bladder inflammation.

Correct Answer: A

Rationale: The 'fight or flight' response is a primal physiological reaction that prepares the body to respond to a perceived threat or danger. This response triggers an increase in heart rate to pump more blood to the muscles and vital organs, preparing the body for action. Choice B, 'Constricted pupils,' is part of the 'fight or flight' response as well, as it helps improve focus and vision. Choice C, 'Decreased blood pressure,' is incorrect because blood pressure typically increases to ensure adequate circulation during the 'fight or flight' response. Choice D, 'Decreased heart rate,' is incorrect as the heart rate increases to supply more oxygen and nutrients to the body during times of stress.

Correct Answer: B

Rationale: The correct answer is B: Severe diarrhea. A patient who has recently returned from a trip to Nepal with a nongovernmental organization and is seeking care for amebiasis would most likely have been prompted by the symptom of severe diarrhea. Amebiasis is an infection caused by the parasite Entamoeba histolytica, commonly transmitted through contaminated food or water sources in developing countries like Nepal. The hallmark symptom of amebiasis is dysentery, which is characterized by severe diarrhea with blood or mucus in the stool. Malaise and fatigue (choice A) are nonspecific symptoms that may accompany many illnesses and are not specific to amebiasis. Intermittent fever (choice C) is not a typical presenting symptom of amebiasis, which primarily manifests with gastrointestinal symptoms. Dizziness and confusion (choice D) are also not typical symptoms associated with amebiasis.