Correct Answer: A

Rationale: The correct answer is A: 'To transport oxygen and nutrients.' The primary function of the cardiovascular system is to transport oxygen, nutrients, and hormones to cells throughout the body and remove waste products. Choice B is incorrect because regulating body temperature is primarily the function of the body's thermoregulatory system, including sweat glands and blood vessels near the skin surface. Choice C is incorrect because while the cardiovascular system does help remove waste products through circulation, it is not its primary function. Choice D is incorrect as hormone production is mainly carried out by endocrine glands, not the cardiovascular system.

Correct Answer: C

Rationale: The correct answer is C: Cortisol. Cortisol, produced by the adrenal glands, is involved in the body's stress response. It helps regulate metabolism, immune function, and the body's response to stressors by increasing blood sugar levels, suppressing the immune system, and aiding in the metabolism of fats, carbohydrates, and proteins. Choice A, Insulin, is a hormone that regulates blood sugar levels and is not primarily involved in the stress response. Choice B, Adrenaline, is also known as epinephrine and is involved in the fight-or-flight response, which is related to stress but is not the main hormone in the body's stress response. Choice D, Melatonin, is a hormone that regulates sleep-wake cycles and is not directly involved in the stress response.

Correct Answer: B

Rationale: The ulnar nerve innervates the forearm and hand, specifically providing sensation to the ring and little fingers. Damage to this nerve can lead to decreased sensation in these areas, making the arm the correct answer. Choices A, C, and D are incorrect because the ulnar nerve does not supply sensation to the leg, face, or abdomen.

Correct Answer: B

Rationale: The correct answer is B: To produce bile. The liver's primary function in the digestive system is to produce bile. Bile is essential for the digestion and absorption of fats in the small intestine. It helps emulsify fats, making it easier for enzymes to break them down into smaller molecules for absorption. Choices A, C, and D are incorrect as storing glucose is primarily done in the liver for energy maintenance, detoxifying harmful substances is a function of the liver related to metabolism but not specifically in the digestive system, and absorbing nutrients is mainly done in the small intestine rather than the liver.

Correct Answer: B

Rationale: Tendons are the correct answer. They are strong connective tissues that connect muscles to bones, allowing movement when muscles contract. Ligaments connect bones to other bones, providing joint stability. Cartilage is a firm, flexible connective tissue present in joints and the outer ear. Fascia is a connective tissue that surrounds muscles, blood vessels, and nerves, offering support and protection. Therefore, the correct tissue type that connects muscles to bones is tendons.