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: Dental
Test for vitality testing is /are: 
Select and explain. 
A. Measurement of crot surface temperature., B. Dual wavelength spectrometry., C. Transmitted light photo plathysmography., D. All of the above.
D: All of the above.
Answer: D: All of the above. 
Explanation: Other than these Xe133 radioisotope is also used for vitality testing.