theres a question that i'm unsure about. It came from a past hsc paper. But i dont have answers nor do i know which year it came from. So if anyone knows the answer... feel free to type it up 
An understanding of Le Chatlier's Principle is important in the chemical industry. which prediction can be made using this principle?
a. the identity of products of a chemical reaction
b. the effect of changes in temperature on the rates of reaction
c. the effect of catalysts on the position of equilibrium reactions
d. teh effect of changes in the concentration of chemical substances in equilibrium
im contemplating b and d but i dont know how one of them could be wrong
An understanding of Le Chatlier's Principle is important in the chemical industry. which prediction can be made using this principle?
a. the identity of products of a chemical reaction
b. the effect of changes in temperature on the rates of reaction
c. the effect of catalysts on the position of equilibrium reactions
d. teh effect of changes in the concentration of chemical substances in equilibrium
im contemplating b and d but i dont know how one of them could be wrong