Inconsistent units for Kc prevent accurate calculation

Steps:

• The reaction's Kc should have units dm^3 mol^{-1} based on Δn = -1.
• Given units dm^6 mol^{-2} do not match, making the numerical value of K ambiguous.
• The relation [SO2] = 2 [O2] and [SO3] = 6.20 mol dm^{-3} cannot be used reliably without correct units.
• Not enough information to solve for [SO2].

Why D is correct:

• Not enough information.

Why the others are wrong:

• A: Not enough information.
• B: Not enough information.
• C: Not enough information.

Final answer: Not enough information.