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
Vital staining was introduced by: 
Select and explain. 
A. Enlow, B. Wolff, C. John Hunter, D. Petrovic
C: John Hunter
Answer: C: John Hunter 
Explanation: Vital staining is an experimental method of measuring growth. It was introduced by John Hunter in the eighteenth century. The method consists of injecting dyes that stain the mineralizing tissues. These dyes get deposited in the bones and teeth and the animals are sacrificed and tissues studied histologically. Hunter studied the growth of mandible in the pig.