For the reaction A $\rightarrow$ B, the K_eq' is 10^-6. If a reaction mixture originally contains 1 mmol of A and 1 mmol of B, which statement must be TRUE?

A) At equilibrium, there will be still be equal levels of A and B.
B) The rate of the reaction is very slow.
C) At equilibrium, the amount of A will greatly exceed the amount of B.
D) The reaction will proceed toward B at a very high rate.
E) $\Delta$ G'° for the reaction will be large and positive.