The reaction \[X\to Y\] is an exothermic reaction. Activation energy of the reaction for X into Y is\[150\,kJ\,mo{{l}^{-1}}\]. Enthalpy of reaction is\[135\text{ }k\,J\,mo{{l}^{-1}}\]. The activation energy for the reverse reaction, \[Y\to X\] will be:

• A. \[280\,kJ\,mo{{l}^{-1}}\]                     
• B. \[285\text{ }kJmo{{l}^{-1}}\]
• C. \[270\text{ }kJ\,mo{{l}^{-1}}\]            
• D. \[15\,kJ\,mo{{l}^{-1}}\]