The Phosphorylation of Creatine (Cr)by ATP Forming Creatine Phosphate (Cr-P)is $\Delta$

The phosphorylation of creatine (Cr) by ATP forming creatine phosphate (Cr-P) is rather endergonic ( $\Delta$ G°´ = + 12.6 kJ/mol) . Which of the following explains how this reaction proceeds in a typical muscle cell?

A) in the cytosol, [ATP] is high and [Cr] is high allowing the reaction to proceed
B) in the mitochondria, [ATP] is high and [Cr-P] is low allowing the reaction to proceed
C) Cr-P is rapidly transported across the cellular membrane allowing for high levels of Cr-P in the cytosol
D) in the mitochondria, [ADP] is high allowing phosphorylation of Cr to occur
E) none of the above