For the equilibrium system \[2HX(g)\rightleftharpoons {{H}_{2}}(g)+{{X}_{2}}(g)\] the equilibrium constant is \[1.0\times {{10}^{-5}}\]. What is the concentration of HX if the equilibrium concentration of \[{{H}_{2}}\] and \[{{X}_{2}}\] are\[1.2\times {{10}^{-3}}M\], and \[1.2\times {{10}^{-4}}M\] respectively.

• A. \[12\times {{10}^{-4}}M\]        
• B. \[12\times {{10}^{-3}}M\]
• C. \[12\times {{10}^{-2}}M\]        
• D. \[12\times {{10}^{-1}}M\]