Final answer:
Insulin and glucagon are hormones that regulate blood sugar levels, with insulin decreasing and glucagon increasing the levels to maintain homeostasis.
Step-by-step explanation:
The roles of insulin and glucagon in blood sugar control are critical for maintaining homeostasis of blood glucose levels. Insulin, which is secreted by the pancreas when blood glucose levels are high, works to decrease blood sugar levels by stimulating cells to take in glucose and by promoting the conversion of glucose into glycogen.
On the other hand, glucagon is released when blood glucose levels are low and functions to increase blood sugar levels by stimulating the breakdown of glycogen into glucose in the liver. Therefore, the correct answer is 2) Insulin decreases blood sugar levels, while glucagon increases blood sugar levels.