The lungs are the main organs of respiration and are responsible for the exchange of oxygen and

Correct Answer: C

Rationale: The correct answer is C: Carbon dioxide. The lungs exchange oxygen from the air we breathe with carbon dioxide produced by our cells. Oxygen is taken up by red blood cells in the lungs and transported to the body tissues, while carbon dioxide is released from the tissues into the bloodstream and then exhaled through the lungs. Nitrogen (choice A) is not involved in the gas exchange process. Hydrogen (choice B) is not a primary gas exchanged during respiration. Carbon monoxide (choice D) is a toxic gas that can interfere with oxygen transport but is not a normal part of the respiratory exchange process.

Correct Answer: C

Rationale: The correct answer is C: Iodine. Iodine is essential for thyroid hormone production, which regulates metabolism. Common table salt is often iodized to prevent iodine deficiency. Potassium (A) is important for heart and muscle function, but not specifically for thyroid function. Magnesium (B) plays various roles in the body but is not directly related to thyroid function. Copper (D) is involved in enzyme function but is not a primary mineral for thyroid gland function.

Correct Answer: B

Rationale: The correct answer is B: Assistive device. Assistive devices are designed to help disabled individuals perform daily activities. They can include wheelchairs, hearing aids, and adaptive tools. Orthotic devices (A) are used for support or alignment, not specifically for daily activities. Restorative devices (C) aim to improve function, not solely assist in daily living. Range of motion devices (D) focus on movement limitations, not daily tasks. Therefore, B is the best choice for devices aiding in daily living activities.

Correct Answer: C

Rationale: The correct answer is C: Bereavement. Bereavement refers to the period following a loss in which mourning occurs. It is a time of grieving and coming to terms with the loss. Breakthrough is unrelated, burnout refers to exhaustion, and blackout denotes a loss of consciousness. Bereavement specifically addresses the process of mourning and coping with loss.

Correct Answer: D

Rationale: Preoperative enemas clear the colon, reducing contamination risk since peristalsis is delayed post-surgery.