How many of the following statements are the limitations of Ellingham diagram? 

a) Does not say about the kinetics of the reduction process.
b) It is presumed that the reactants and products are in equilibrium.
c) Ellingham diagram can not answer questions like how fast the reduction reaction could be? 
d) The melting is indicated by an abrupt change in the curve.
e) This graph provides a sound basis for considering the choice of reducing agent in the reduction of oxides
f) This graph help us in predicting the feasibility of thermal reduction of an ore