Arteries are strong, elastic vessels that carry blood to the heart.

This is because it is an example of a positive feedback loop, which amplifies the change and moves the system away from its normal state.
A negative feedback loop is a mechanism that reverses a deviation from the set point and maintains homeostasis.
Choice A is wrong because increasing heart rate and force of contraction when blood pressure falls is a negative feedback loop that restores blood pressure to normal.
Choice B is wrong because secreting insulin after a meal to return blood sugar concentration toward normal is a negative feedback loop that regulates glucose levels.
Choice D is wrong because shivering when body temperature falls below normal is a negative feedback loop that increases heat production and raises body temperature.
Normal ranges for blood pressure are 90/60 mmHg to 120/80 mmHg, for blood glucose, are 70 mg/dL to 140 mg/dL, and for body temperature are 36.5°C to 37.5°C or 97.7°F to 99.5°F.

The fibrous pericardium is the loose-fitting sac around the heart that protects it and anchors it to surrounding structures.

Choice B is wrong because the epicardium is the outer layer of the heart wall, also called the visceral pericardium, and it is not a sac.
Choice C is wrong because the endocardium is the inner layer of the heart wall that forms the lining of all heart chambers, and it is not a sac.
Choice D is wrong because the visceral pericardium is another name for the epicardium, and it is not a loose-fitting sac.