The primary reason an increase in temperature results in an increase
in the reaction rate is that the:
a. number of particles with the required activation energy increases.
b. potential energy of the particles increases.
c. force of attraction between the particles increases

Hello teatea,

The correct answer is A.

“Increase in temperature increases Reaction Rate for two reasons: 
i) The molecules move faster & therefore collide more often 
ii) The greater proportion of molecules will now have the activation
energy for the reaction & so have sufficient energy when they
collide.”

From “Collision Theory” by Mohsin Ali and Stephen Walsh.  Part of
their Chemistry Website, produced at Oatlands College and hosted on
the web site of the Dublin Institute of Technology, Republic of
Ireland.
http://www.dit.ie/DIT/science/chemistry/rsccomp/competition00/multi/collisiontheory.htm

search strategy: temperature, “reaction rate” molecules “activation
energy”