Answer: Option (d) is the correct answer.
Explanation:
When a reactant breaks into two or more number of products then the reaction is known as decomposition reaction.
Out of the given options, option (d) that is [tex]2H_{2}O(l)\rightarrow 2H_{2}(g) + O_{2}(g)[/tex], is a decomposition reaction.
As here, the [tex]H_{2}O[/tex] molecule is breaking into hydrogen and oxygen. Hence, two products are obtained.
Thus, option (d) is the decomposition reaction.