GKFix MCQ Question

Which of the following reactions represents a formation reaction?

• A. CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)
• B. C(diamond) + 2H₂(g) → CH₄(g)
• C. C(graphite) + 2H₂(g) → CH₄(g)
• D. 2C(s) + 3H₂(g) → C₂H₆(g)