Pick the appropriate choice about collision theory of reaction rates. 
I) It explains the effect of temperature on rate of reaction

II) It assumes that the reactants must be in correct orientation to react.
III) It says rate depends upon the frequency at which reactants collide. 

IV) The collisions having energy higher than the threshold value will give successful reactions. The correct points are

According to collision theory rate of reaction = ${\mathrm{PZe}}^{-\frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{RT}}}$

It explains 

(1) dependence of rate of reaction on temperature

(2) P = probability that orientation of a collision is correct 

(3) with increase in temperature,avereage speed increases and frequency of collisions increases.

(4) Fraction of molecules having energy greater than activation energy increases with increase in temperature and collisions between them brings a chemical reaction