On increasing the temperature, the rate of reaction increases mainly because

Explanation

The correct answer is:(c) Collision frequency increasesHere's why the other options are incorrect:(a) The activation energy of the reaction increases: This is the opposite of what happens when temperature increases. Higher temperatures provide more kinetic energy to the molecules, making it easier for them to reach the activation energy and react.(b) Concentration of the reacting molecules increases: While temperature can indirectly affect concentration (e.g., by causing expansion of gaseous reactants), this is not the main reason for the increased reaction rate. The primary factor is the increased collision frequency.(d) None of these: As explained above, collision frequency is the main reason for the increased reaction rate with increasing temperature.Here's a more detailed explanation of why collision frequency increases with temperature: