Which of the following statements about the zeolites is false?

Options

A. They are used as cation exchangers
B. They have open structure which enables them to take up small molecules
C. Zeolites are aluminosilicates having three dimensional network
D. Some of the `SiO_(4)^(4-)` units ar replaced by `AlO_(4)^(5-)` and concentrated ions in zeolites