Pyrosilicates have _________________ structural unit :
List IList IIA. Bi3+⟶(BiO)+p. HeatB. [AlO2]−⟶Al(OH)3q. HydrolysisC. SiO4−4⟶Si2O6−7r. AcidificationD. (B4O2−7)⟶B(OH)3s. dilution by water
Si3O6−9(having three tetrahedral units) is represented as :