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
The short term effects of radiation on a tissue are determined by the sensitivity of its: 
Select and explain. 
A. Mesenchymal cells, B. Ectodermal cells, C. Parenchymal cells, D. None of the above
C: Parenchymal cells
Answer: C: Parenchymal cells 
Explanation: The short-term effects of radiation on a tissue (effects seen in the first days or weeks after exposure) are determined primarily by the sensitivity of its parenchymal cells.
White and Pharoah's Oral Radiology Principles and Interpretation,7th edition