Insulin lowers blood glucose levels

Steps:

• Recall that blood glucose regulation involves hormones from the pancreas responding to sugar intake.
• Identify hormones that raise glucose: glucagon and adrenaline promote glycogen breakdown.
• Recognize insulin as the hormone secreted after meals to handle excess glucose.
• Confirm insulin facilitates glucose uptake into cells, reducing blood levels.

Why C is correct:

• Insulin, produced by beta cells in the pancreas, binds to receptors on cells to promote glucose transport inside, directly lowering blood concentration per cellular uptake mechanism.

Why the others are wrong:

• A. Adrenaline raises blood glucose by stimulating glycogenolysis during stress.
• B. Glucagon increases blood glucose by triggering liver glycogen breakdown.
• D. Testosterone regulates male traits and reproduction, not glucose levels.

Final answer: C