Correct Answer: B

Rationale: The primary role of cytokines in maintaining homeostasis is to perform a regulatory function in the development of diverse blood cells. Cytokines act as signaling molecules that regulate the immune response and hematopoiesis. Choice A is incorrect because cytokines do not perform phagocytosis; they regulate immune responses. Choice C is incorrect because while cytokines are involved in the formation of some blood cells, they are not considered the basic 'building blocks' of all blood cells. Choice D is incorrect because cytokines are not formed in response to antibodies, but rather play a role in the immune response to various stimuli.

Correct Answer: B

Rationale: The correct answer is B: Jaundice. Isoniazid (INH) is known to cause hepatotoxicity, which can manifest as jaundice. Jaundice is a serious adverse effect that warrants immediate discontinuation of the medication to prevent further liver damage. Weight gain, fever, and arthralgia are not typically associated with isoniazid use and would not necessitate discontinuation of the medication.

Correct Answer: B

Rationale: The correct answer is B: Smoking. Smoking is the primary risk factor for developing lung cancer. Tobacco smoke contains numerous carcinogens that can damage the cells in the lungs, leading to the development of cancer. Alcohol consumption (Choice A), poor diet (Choice C), and environmental exposure (Choice D) can contribute to overall health risks, but they are not the primary risk factors specifically associated with the development of lung cancer.

Correct Answer: B

Rationale: The correct answer is B: Increased gastric motility. The parasympathetic nervous system is known to promote rest and digest functions, which includes increasing gastric motility to aid in digestion. Choices A, C, and D are incorrect as they are more characteristic of the sympathetic nervous system. The sympathetic nervous system is responsible for the fight or flight response, leading to increased heart rate (Choice A), pupil dilation (Choice C), and sweating (Choice D) among other responses.

Correct Answer: A

Rationale: The correct answer is A: Weight gain, mood changes, and nausea are common side effects of oral contraceptives. Weight gain may occur due to fluid retention or changes in metabolism. Mood changes can be caused by hormonal fluctuations. Nausea is a common side effect that usually improves after a few months of use. Choices B, C, and D are incorrect because they do not reflect common side effects associated with oral contraceptives. Increased appetite, insomnia, breast tenderness, headaches, dizziness, fatigue, hair loss, and joint pain are not typically reported side effects of oral contraceptives.