All members of groups 14 when heated in oxygen form oxides. Which of the following is the correct trend of oixdes?
A. Dioxides `CO_(2), SiO_(2)` and `GeO_(2)` are acidic while `SnO_(2)` and `PbO_(2)` are amphoteric
B. CI,GeO, SnO and PbO are amphoteric
C. Monoxides react with haemoglobin to form toxic compounds.
D. All oxides burn with blue flame.
