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
To make the vinyl polysiloxane hydrophilic the following is added: 
Select and explain. 
A. Mineral oil, B. Surfactant, C. Water, D. Plasticizer
B: Surfactant
Answer: B: Surfactant 
Explanation: None