Whivh statement about zeolite is false ?
A. They are used as cation exchanger
B. They have open structure which enables them to take up small molecules
C. Zeolites are alumino silicates having three dimensional networks
D. Some of the `SiO_(4)^(4-)` units are replaced by `AlO_(4)^(5-)` and `AlO_(6)^(9-)` ions in zeolites