Solid Sodium Chloride and Solid Silver Nitrate React to Form

Multiple Choice

Solid sodium chloride and solid silver nitrate react to form sodium nitrate and silver chloride. The reaction is extremely slow. However, if the sodium chloride and silver nitrate are first dissolved in water and the two solutions are mixed, the reaction occurs very rapidly. Which of the following explains the difference in reaction rates?

A) Ions in solution have high mobility, and ions of opposite charges are attracted to each other.
B) The concentration of ions in solution is greater than the concentration of ions in the solid.
C) Sodium chloride solution does not react with solid silver nitrate.
D) Silver nitrate solution does not react with solid sodium chloride.