What is the molecular formula if the molar mass is 234.0 g/mole and the empirical formula is C₅O₂NH₁₁?
a) C₅O₂NH₁₁
b) C₁₀O₄NH₂₂
c) C₁₅O₆NH₃₃
d) C₂₀O₈NH₅₅