Which methods can be used to monitor the progress of this reaction?

\(\begin{array}{*{20}{l}} {{\text{I.}}}&{{\text{Change in colour of this reaction mixture}}} \\ {{\text{II.}}}&{{\text{Change in mass of this reaction mixture}}} \\ {{\text{III.}}}&{{\text{Change in volume of gas evolved}}} \end{array}\)

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

C