Exchange of gases takes place in which of the following organ?

Correct Answer: B

Rationale: Gas exchange refers to the physiological process where oxygen is absorbed into the bloodstream and carbon dioxide is expelled from it, occurring primarily in the lungs (B). This happens in the alveoli, tiny air sacs where oxygen diffuses into pulmonary capillaries and carbon dioxide moves out to be exhaled. The kidneys (A) regulate fluid and electrolyte balance, not gas exchange. The liver (C) metabolizes nutrients and detoxifies substances but has no role in respiration. The heart (D) pumps blood, facilitating circulation, but does not perform gas exchange. The lungs' unique structure alveoli surrounded by capillaries enables efficient diffusion driven by concentration gradients, making B the correct answer. This process is vital for oxygenation of tissues and removal of metabolic waste, underscoring the lungs' respiratory function.

Correct Answer: C

Rationale: Mrs. Gary as proxy when Mr. Gary is unconscious is a health care proxy (C), per legal terms designated decision-maker. Living will (A) states wishes, DNR (B) bars CPR, bill of rights (D) ensures care. C fits surrogate role, making it correct.

Correct Answer: B

Rationale: Ethics are moral principles governing behavior (B), per philosophy guiding right/wrong in nursing. Hospital rules (A), state laws (C), or law-moral mix (D) are narrower. B best captures ethics' broad moral scope, making it correct.

Correct Answer: B

Rationale: Ethics committees address dilemmas (B), per their role resolving conflicts (e.g., treatment disputes). Rules (A) and laws (D) are administrative/legislative, punishment (C) disciplinary not ethics-focused. B aligns with committee purpose, making it correct.

Correct Answer: D

Rationale: Advocates protect rights (A), mediate (B), inform (C) 'overrides decision' (D) isn't true, contradicts autonomy, per nursing role. D's control opposes advocacy, making it untrue.