In the given chemical reaction, aFe203 (s) + bCO(g) [REPLACEMENT] cFe (s) + dC02, we need to determine the appropriate values of coefficients a, b, c, and d to balance the equation.

To balance a chemical equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation.

Let`s analyze the options:

Option 1: 3, 2, 3, 1

This option suggests that there are 3 Fe203 molecules and 2 CO molecules on the left side, and 3 Fe molecules and 1 CO2 molecule on the right side. However, this does not balance the equation since the number of O atoms is different on both sides.

Option 2: 1, 3, 2, 3

This option implies that there is 1 Fe203 molecule and 3 CO molecules on the left side, and 2 Fe molecules and 3 CO2 molecules on the right side. This balances the equation because the number of atoms of each element is the same on both sides. Therefore, this is the correct answer.

Option 3: 2, 3, 3, 1

This option suggests