Consider the reaction : \[{{N}_{2}}+3{{H}_{2}}\to 2N{{H}_{3}}\] carried out at constant temperature and pressure. If \[\Delta H\] and \[\Delta U\] are the enthalpy and internal energy changes for the reaction, which of the following expression is true [AIEEE 2005]

• A.                 \[\Delta H=0\]  
• B.                 \[\Delta H=\Delta U\]
• C.                 \[\Delta H<\Delta U\]   
• D.                 \[\Delta H>\Delta U\]