One of the following is an incorrect statement. Point out the incorrect one.
A. `H_(2)O_(2)`decomposes rapidely in presence of `MnO_(2)`
B. Ice at its melting point is lighter than water because ice crystals have hollow hexagonal arrangement of `H_(2)O` molecules.
C. `D_(2)O` will have maximum density at `11.5^(@)C`.
D. Water gas contains greater proportion of CO than that of `H_(2)`