How Much Charge Can Be Placed on a Capacitor of Plate

Multiple Choice

How much charge can be placed on a capacitor of plate area 20 cm² with air between the plates before it reaches "atmospheric breakdown" where E = 3.0 × 10⁶ V/m? (ε₀ = 8.85 × 10−¹² C²/N⋅m²)

A) 6.6 × 10−⁷ C
B) 2.7 × 10−⁸ C
C) 5.3 × 10−⁸ C
D) 4.0 × 10−⁷ C