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: Pathology
Nanotechnology has found tremendous application in the diagnosis of cancers because of all of following advantages, except 
Select and explain. 
A. Nanocrystals exibit bright, photostable fluorescence, B. Nonocrystals have a narrow spectrum wavelength, C. Peak spectrum wavelength is tunable, D. Nanocrystals exhibit a narrow difference between their excitation and emission peak spectra
D: Nanocrystals exhibit a narrow difference between their excitation and emission peak spectra
Answer: D: Nanocrystals exhibit a narrow difference between their excitation and emission peak spectra 
Explanation: Ans'd. Nanocrystals exhibit a narrow difference between their excitation and emission peak spectra