Diagram (in attached figure)

In the N field as the reaction would be An+wo = Gros + quartz if the Wo is in excess some will remain as leftout and all the An will be consumed Reaction will proceed from M to N

Ans: (C) On the univarient lime separating the two fields. Gros+Qtz+Wo can occur in the equilibrium condition i.e. on the line separating the two fields.