9. Estimate the pressure needed to make two deuterons fused into a helium nucleus assuming the Coulomb force to confine deuterons is uniformly distributed on the surface of a 2 fm radius sphere. (A) 5 × 10¹⁰ N/m² (B) 5 × 10¹⁵ N/m² (C) 5 × 10²⁰ N/m² (D) 5 × 10²⁵ N/m² (E) 5 × 10³⁰ N/m²