Final answer:
Glucagon and insulin are hormone antagonists because they have opposing effects on blood glucose levels; glucagon increases it while insulin decreases it.B. Glucagon and insulin
Step-by-step explanation:
Among the options provided, the set of hormones that are antagonists are glucagon and insulin. These two hormones have opposite effects on blood glucose levels. Glucagon is produced by the alpha cells of the pancreas and raises blood glucose by promoting the conversion of glycogen to glucose in the liver. On the other hand, insulin is produced by the beta cells of the pancreas and lowers blood glucose levels by facilitating the uptake of glucose by cells, especially muscle and fat cells, and also by promoting the conversion of glucose into glycogen in the liver. This mechanism of opposing actions makes glucagon and insulin a classic example of hormone antagonists in the human body.
The other hormone pairs listed such as T3 & T4, Epinephrine & Cortisol, and Growth Hormone and thyroxine do not function as antagonists to each other, but rather have different roles in the body's physiology.