How temperature affects reaction rate

Increasing the temperatureincreases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for thereaction) which result in areaction.

I am not sure but as i remember, if the temperature is high, the reaction rate increases :)  

It is the ionization property of water that separates the Oxygen and Hydrogen present in the compound of water creating positive and negative ions for chemical reactions to take place. Therefore the answer is (a).