Before Any Professionally Applied Gel or Foam Fluoride Treatment,the Dental

Before any professionally applied gel or foam fluoride treatment,the dental hygienist must ensure that which of the following is done?

A) All oral biofilm is removed to facilitate greater fluoride uptake by the tooth surface.
B) The client is placed in a semisupine position to increase operator visibility.
C) The teeth are dried with compressed air or gauze to prevent dilution of the fluoride.
D) A lubricant is applied over composite restorations to prevent their dissolution.