Answer:
Option A is correct = combustion
Explanation:
When substance react with oxygen combustion is occur. The substance which burned is called fuel and in this process large amount of heat is released to the surrounding. It is exothermic process.
For example:
4Li + O₂ → 2Li₂O
2Mg + O₂ → 2MgO
S + O₂ → SO₂
The product which is formed as a result of combustion reaction are called oxides.
In given examples we can see that lithium, magnesium and sulfur react with oxygen and product formed is oxides of respective elements such as lithium oxide ( Li₂O), magnesium oxide (MgO) and sulfur oxide ( SO₂ ).
Other options are incorrect because:
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
