Match List-I with List-II.
Choose the correct answer from the options given below :}

Consider the following reaction sequence.

One mole each of \(A_2(g)\) and \(B_2(g)\) are taken in a 1 L closed flask and allowed to establish the equilibrium at 500 K: \(A_{2}(g)+B_{2}(g) \rightleftharpoons 2AB(g)\). The value of x (missing enthalpy of \(B_2\) or related parameter) is ______ . (Nearest integer)}