Consider the following data for the reaction 
$$\text{X}_2(g) + \text{Y}_2(g) \rightleftharpoons 2\text{XY}(g)$$
at 600 K.  The $$\Delta_r G^\circ$$ (in $$kJ/mol^{-1}$$) for the reaction is :

A

$$-21000$$

B

$$-10$$

C

$$-1000$$

D

$$-9.012$$