I Am Performing a Reaction, a → B, with Δ

Multiple Choice

I am performing a reaction, A → B, with Δ G ° ' = − 5000 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 8 mM A and 2 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 Δ G ° '