Bond energies of C−H,C≡C,C=C and H−H bonds are 414, 827,606 and 430 kJmol⁻¹ respectively. The enthalpy of hydrogenation of C₂H₂( g) to C₂H₄(g) will be
a. −127 kJ mol⁻¹
b. −215 kJ mol⁻¹
c. −177 kJ mol⁻¹
d. −285 kJ mol⁻¹