The correct answer is option C
2Al + 3Ag₂S → 6Ag + Al₂S₃
In a balanced reaction the number of atoms of different elements is equal on both side of the reaction.
Reactant side: 2 atoms of Al, 6 atoms of Ag and 3 atoms of S.
Product side: 6 atoms of Ag, 2 atoms of Al and 3 atoms of S.
This is an example of a single replacement reaction as the free elemental Al replaces Ag from the Ag₂S to form free elemental Ag and Al₂S₃ compound.
