Question

guys help me in this question

Answer 1

In this reaction Carbon(C) gets reduced in Carbon dioxide(CO2) and acts as a oxidizing agent for Magnesium(Mg).

So your answer is Option D

Answer 2

$\huge \sf{\colorbox{skyblue}{❥︎A᭄ɴsᴡᴇʀ࿐:−}}$

option d because here the carbon dioxide is reduced and it became carbon

and magnesium is oxidised and it became

$mg {o}^{2}$

which means magnesium oxide

and it is a redox reaction which involves both oxidation and reduction