Correct Answer: C

Rationale: The correct answer is C: Increased secretion of antidiuretic hormone (ADH). Syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by the excessive release of ADH, which leads to water retention and dilution of blood sodium levels. Choices A, B, and D are incorrect because SIADH is not associated with decreased insulin production, decreased ADH production, or increased production of insulin.

Correct Answer: B

Rationale: A pulmonary embolism is commonly caused by a blood clot that originates in the venous system of the lower extremity and travels to the lungs, blocking blood flow. This clot is known as a venous thromboembolism. An autoimmune disorder (Choice A) is not typically associated with pulmonary embolism. Intracranial pressure (Choice C) refers to pressure inside the skull and is unrelated to pulmonary embolism. Hypotension (Choice D) is low blood pressure and is not a common cause of pulmonary embolism.

Correct Answer: A

Rationale: Leukocytosis is a condition characterized by an elevated white blood cell count, typically in response to infection or inflammation. Therefore, the correct answer is an increased white blood cell count (Choice A). Increased platelet count (Choice B) is not a typical finding in leukocytosis. Choices C and D, decreased white blood cell count and decreased platelet count respectively, are opposite to what would be expected in leukocytosis and are therefore incorrect.

Correct Answer: A

Rationale: Renin is the correct answer. When arterial blood pressure decreases, the kidneys release renin, which triggers a series of reactions ultimately leading to an increase in blood pressure and peripheral resistance. Antidiuretic hormone (choice B) is involved in water retention, atrial natriuretic hormone (choice C) promotes sodium excretion and lowers blood pressure, and insulin (choice D) regulates glucose metabolism, not blood pressure.

Correct Answer: A

Rationale: The correct answer is A: Erythropoietin. The kidneys produce erythropoietin to stimulate the production of red blood cells. Insulin and glycogen are not hormones secreted by the kidneys; insulin is produced by the pancreas, and glycogen is a stored form of glucose. Testosterone is a hormone primarily produced by the testes in males and to a lesser extent in females. Thyroid stimulating hormone is produced by the pituitary gland to regulate thyroid function, not red blood cell production.