Hormones

Step 1: Concept
Insulin is a hormone produced by the pancreas that manages energy sources.
Step 2: Analysis
It specifically controls how the body uses and stores carbohydrates.
Step 3: Conclusion
Insulin is the primary regulator of glucose (sugar) metabolism.
Final Answer: (C)

Step 1: Series Regions
Lyman series lies in the Ultraviolet region. Balmer series lies in the Visible region.
Step 2: Higher Series
Paschen, Brackett, and Pfund series all lie in the Infrared region.
Step 3: Conclusion
The Balmer series is the only one visible to the human eye.
Final Answer: (b)