Carbon and CO gas are used to reduce which of the following pairs of metal oxides for extraction of metals?

Options

A. FeO, Sno
B. Sno, ZnO
C. BaO,` Na_2 O_2`
D. `FeO, ZnO`

Explanation

To determine which pairs of metal oxides can be reduced by carbon and carbon monoxide for the extraction of metals, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Reduction**:
- Reduction is the process of gaining electrons or decreasing the oxidation state of a substance. In metallurgy, this often involves converting metal oxides to their corresponding metals using reducing agents like carbon (C) or carbon monoxide (CO).

2. **Analyzing the Options**:
- We have four pairs of metal oxides to consider:
- **Option A**: FeO, SnO
- **Option B**: SnO, ZnO
- **Option C**: BaO, NaO2
- **Option D**: FeO, ZnO

3. **Evaluating Each Pair**:
- **Option A (FeO, SnO)**:
- FeO (Iron(II) oxide) can be reduced by carbon or CO to produce iron (Fe).
- SnO (Tin(II) oxide) can also be reduced by carbon or CO to produce tin (Sn).
- Both can be reduced, so this option is valid.

- **Option B (SnO, ZnO)**:
- SnO can be reduced by carbon or CO to produce tin.
- ZnO (Zinc oxide) can also be reduced by carbon or CO to produce zinc (Zn).
- Both can be reduced, so this option is also valid.

- **Option C (BaO, NaO2)**:
- BaO (Barium oxide) is not typically reduced by carbon or CO in metallurgical processes.
- NaO2 (Sodium superoxide) is not reduced by carbon or CO either.
- Therefore, this option is not valid.

- **Option D (FeO, ZnO)**:
- FeO can be reduced by carbon or CO to produce iron.
- ZnO can also be reduced by carbon or CO to produce zinc.
- Both can be reduced, so this option is valid.

4. **Conclusion**:
- The pairs of metal oxides that can be reduced by carbon and carbon monoxide for the extraction of metals are:
- **FeO and ZnO** (Option D).

### Final Answer:
The correct answer is **FeO and ZnO**.