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
Plaster of paris is mixed in 
Select and explain. 
A. Plastic bowl, B. Rubber bowl, C. Glass bowl, D. Metal bowl
B: Rubber bowl
Answer: B: Rubber bowl 
Explanation: Spatulation can be continued by hand using a spatula with a stiff blade with the bowl on a vibrator or a power-driven mechanical spatulator.