Classify the following reaction: 2Mg(s)+O2(g)=>2MgO(s)
a.
combustion

b.
oxidation-reduction

c.
a-c are all correct.

d.
synthesis

e.
two of the above

This is an incomplete question, here is a complete question.

Classify the following reaction:

a.  oxidation-reduction

b.  combustion

c. synthesis

d.  two of the above

e.  a-c are all correct.

Answer : The correct option is, (e) a-c are all correct.

Explanation :

Synthesis reaction : A chemical reaction where multiple substances or reactants combine to form a single product.

It is represented as,

Combustion reaction : A chemical reaction in which a hydrocarbon reaction with the oxygen to give product as carbon dioxide and water.

It is represented as,

Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases.

The given chemical reaction is:

It is an oxidation-reduction reaction in which Mg shows oxidation because  the oxidation state of Mg changes from (0) to (+2) and O  shows reduction because  the oxidation state of O  changes from (0) to (-2).

This reaction is also a synthesis reaction because two reactants combine to form single product.

Hence, the correct option is, (e) a-c are all correct.