मधुमेह या द्रव्याच्या कमतरतेमुळे होतो.

The correct answer is Option C (Insulin). [Note: This question was officially cancelled (#) by MPSC in the final key, but this option is selectable for online practice].

Key Points:
• Commission Note: This question was officially cancelled (#) by MPSC in the final key (due to typographical or option discrepancies). For online evaluation and practice, this primary option is enabled.
• Question Cancelled by MPSC: This question was officially cancelled (marked with #) in the MPSC Final Answer Key for Set A.
• Diabetes Mellitus (मधुमेह) is caused by the absolute deficiency or insufficient secretion/action of the peptide hormone Insulin.
• Insulin is synthesized and secreted by the Beta (β) cells of the Islets of Langerhans in the Pancreas (स्वादुपिंड).
• Function: Insulin facilitates cellular glucose uptake, converting excess blood glucose into stored glycogen (glycogenesis). Its deficiency causes hyperglycemia (high blood sugar levels).
• Discovery: Insulin was discovered in 1921 by Sir Frederick Banting and Charles Best.