Identify the incorrect statement from the following :

(D) Carbon has a strong tendency to form \(p \pi-p \pi\) multiple bonds with itself, such as in alkenes and alkynes. Thus, the first statement is correct.
\(BCl _3\) exists as a monomer because boron cannot expand its octet to form a dimer, whereas \(AlCl _3\) exists as a dimer  
\(\left( Al _2 Cl _6\right)\) complete its octet. Thus, the second statement is correct.
The catenation property depends on the element-element bond strength. The bond enthalpy decreases down the group, so the order of catenation is \(C \gg S i>G e \approx S n\). Thus, the third statement is correct.
Oxygen exhibits a -2 oxidation state in most of its compounds, but it also exhibits a -1 oxidation state in peroxides (e.g., \(H _2 O _2\) ), a \(-1 / 2\) oxidation state in superoxides (e.g., \(KO _2\) ), and positive oxidation states when bonded to fluorine (e.g., +2 in \(OF _2\) and +1 in \(O _2 F_2\) ). Thus, the fourth statement is incorrect.