Correct Answer: A

Rationale: The glomerulus is the correct answer. It is a vital structure in the kidney responsible for filtering blood. The glomerulus is a network of capillaries that filters waste products and excess substances from the blood to form urine. While the Bowman's capsule, Loop of Henle, and Collecting duct are also essential components of the nephron, the primary site of blood filtration occurs at the glomerulus. The Bowman's capsule surrounds the glomerulus and collects the filtered fluid, the Loop of Henle reabsorbs water and important ions, and the Collecting duct further concentrates the urine, but none of these structures are primarily responsible for filtering blood as the glomerulus is.

Correct Answer: B

Rationale: The correct answer is B: Remove carbon dioxide from the body. The primary function of the lymphatic system is to return excess tissue fluid to the bloodstream and assist in the body's defense against infections by filtering out harmful pathogens and foreign particles. Choices A, C, and D are incorrect because transporting oxygen to cells is mainly done by the circulatory system, hormone production is primarily carried out by endocrine glands, and nutrient transport is also a function of the circulatory system and the digestive system, not the lymphatic system.

Correct Answer: B

Rationale: The correct function of the lungs in the respiratory system is to exchange gases. The lungs facilitate the exchange of oxygen and carbon dioxide between the air we breathe in and the blood, ensuring oxygen is absorbed and carbon dioxide is removed during respiration. Choice A is incorrect as the kidneys, not the lungs, filter blood. Choice C is incorrect as energy production primarily occurs in cells, not in the lungs. Choice D is incorrect as waste removal, such as the excretion of carbon dioxide, is a function of the lungs, but the primary function is the exchange of gases.

Correct Answer: B

Rationale: Platelets, also known as thrombocytes, are responsible for clotting blood. When there is an injury, platelets help form blood clots to prevent excessive bleeding. This function is crucial in maintaining hemostasis and preventing hemorrhage. Choices A, C, and D are incorrect. Platelets do not transport oxygen, fight infection, or transport nutrients in the blood.

Correct Answer: A

Rationale: The correct answer is Vitamin C. Vitamin C is essential for the absorption of iron, especially from plant-based sources. It aids in converting non-heme iron (found in plants) into a form that is easier for the body to absorb. This is crucial in preventing iron-deficiency anemia, making Vitamin C a key nutrient for overall health. Vitamin D (choice B) is important for calcium absorption and bone health, not iron absorption. Vitamin K (choice C) plays a role in blood clotting and bone metabolism, not iron absorption. Vitamin B12 (choice D) is important for red blood cell formation and neurological function but is not directly involved in iron absorption.