Which of the following ores can be reduced by carbon?

a. Haematite

b. Zincite

c. Iron pyrites

d. Sphalerite

Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d

HINT: Oxide ore can be reduced by carbon.
Explanation:
STEP 1: In the metallurgical process, the oxide ores are reduced by carbon. Sulphide ore cannot be reduced by carbon.
Here, haematite $\left({\mathrm{Fe}}_{2}{\mathrm{O}}_{3}\right)$ and zincite $\left(\mathrm{ZnO}\right)$ are oxide ores of iron and zinc respectively while iron pyrites $\left({\mathrm{FeS}}_{2}\right)$ and sphalerite $\left(\mathrm{ZnS}\right)$ are sulphide ores of iron and zinc respectively.
STEP 2: The reactions involved are:
Therefore, haematite and zincite can be reduced by carbon.