This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Which of the following layer of epithelium of oral mucous membrane is most sensitive to radiation? 
Select and explain. 
A. Stratum spinosum, B. Stratum granulosum, C. Stratum basale, D. Stratum corneum
C: Stratum basale
Answer: C: Stratum basale 
Explanation: The oral mucosa contains a basal layer composed of rapidly dividing, radiosensitive progenitor cells.
Key Concept:
Rapidly dividing cells are more susceptible to radiation therapy.
White and Pharoah's Oral Radiology Principles and Interpretation 8th edition