This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiotherapy, Subject name: Radiology
Most radiosensitive among the following is 
Select and explain. 
A. Nuclear DNA, B. Mitochondrial DNA, C. Satellite DNA, D. Nucleosomal DNA
D: Nucleosomal DNA
Answer: D: Nucleosomal DNA 
Explanation: (D) Nucleosomal DNA > Among the factors contributing to the distribution of DNA damage within irradiated mammalian cell nuclei are the interactions of DNA with nuclear proteins and the formation of multi-molecular chromatin structures. Studies on the manipulation of chromatin structures of isolated nuclei are summarised.> The majority of chromatin within the nucleus of living cells is tightly compacted into nucleosomal superhelices and other higher order structures which have a limited ability to be damaged by radiation.> The treatment of isolated nuclei with hypotonic buffers causes a decondensation of these structures and markedly sensitises the DNA to radiation, while retaining the majority of the chromosomal proteins