Final answer:
The acid solution used to remove the smear layer and open the enamel rods and dental tubercles is phosphoric acid.
Step-by-step explanation:
The acid solution used to remove the smear layer and open the enamel rods and dental tubercles is phosphoric acid (option c).
Phosphoric acid is commonly used in dentistry as an etchant to prepare tooth surfaces for various procedures, such as bonding of dental restorations and placement of sealants. It helps remove the smear layer, which is a thin layer of debris and debris ions that can hinder the bonding process.
For example, when placing a dental filling, phosphoric acid is applied to the tooth surface for a short period of time. This etching process creates a microscopically rough surface that enhances the adhesion of the dental materials to the tooth structure.