All options are as follow,
A. PbS + O2→ PbO + SO₂
B. PbS + 2O₂→ PbO + 2SO₂
C. 2PbS + 2O₂→ 2PbO + 2SO₂
D. 2PbS + 3O₂→ 2PbO + 2SO₂
E. 3PbS + 3O2→ 2PbO + 2SO2
Option A is not balanced because the number of oxygen atoms are greater at right hand side.
Option B is not balanced because the number of oxygen are less at right hand side and number of sulfur atoms are greater at right hand side.
Option C is not balanced because the number of oxygen atoms are greater at right hand side.
Option D is Balanced, all elements are balanced at both sides.
Option E is not balanced because number of Lead and Sulfur atoms are greater at right hand side.
Result:
Equation in Option D is balanced and correct answer.
