In an isolated system,find the condition for a spontaneous reaction.

• A
  $ \Delta U = 0, \Delta S = 0, \Delta G = 0 $
• B
  $ \Delta U < 0, \Delta S > 0, \Delta G < 0 $
• C
  $ \Delta U = 0, \Delta S > 0 $
• D
  $ \Delta U < 0, \Delta S < 0, \Delta G < 0 $