I Am Performing a Reaction,A B,with DG°' = -0

I am performing a reaction,A B,with DG°' = -0.3 kJ/mol.I start the reaction with 10 mM A and no B.After allowing the reaction to proceed for 24 hrs at room temperature and atmospheric pressure,I analyze a sample of the reaction mix to find I now have 1 mM A and 9 mM B.Which of the following conclusions should I make?

A) The reaction has reached equilibrium.
B) I should come back again later; equilibrium has not yet been reached.
C) The formation of B from A is thermodynamically unfavorable,so I should find another starting material to make B.
D) I must've screwed up; there's no way I could get that result with that DG°'