IAL enthalpy change （题目用英文写） 正确答案是B还是D呢,

There're 2 problems in the question:
1.There's no such a thing as cycloproane (C3H8),The formula of cyclopropane is C3H6.
2.Even if it asked to calculate the enthalpy change of formation of C3H8,its enthalpy change of combustion is still needed.I checked myself,the enthalpy change of combustion of C3H6 is -2091.4 kJ/mol,very close to -2090 kJ/mol in the question.Therefore,C3H8 was an error.If that's the case,the enthalpy change of combustion of H2 is needed,which is -286 kJ/mol.
(i) 3C (s) + 3O2 (g) = 3CO2 (g) ∆H₁ = (-393.7)*2 = -1181.1 kJ
(ii) 3H2 (g) + (3/2)O2 (g) = 3H2O (l) ∆H₂ = (-286)*3 = -858 kJ
(iii) C3H6 (g)+ (9/2)O2 (g) = 3CO2 (g) + 3H2O (l) ∆H₃ = -2090 kJ
(i) + (ii) - (iii):3C(s) + 3H2 (g) = C3H6 (g)
∆H = ∆H₁ + ∆H₂ - ∆H₃
= -1181.1 - 858 - (-2090)
= 50.9 kJ/mol