According to Le Chatelier's principle the favorable conditions for preparation of ammonia by Haber’s process is/are

i) High temperature      ii) Low temperature

iii) Low pressure           iv) High pressure

v) Positive catalyst

In Haber's process NH₃ is prepared by the equation, 

∆H=-92KJ/mol, 

According to Le chatelier’s principle exothermic reactions are more favored at low temperature and the reaction involve decrease in number of gaseous moles favored at high pressure. Positive catalyst favors both forward and backward reactions at equilibrium.