ANSWER
The molecules or ions in solution can freely intermingle
option F
Step-by-step explanation
Collision theory states that "before a product can be formed, the reactants need to collide with each other"
This implies that the reacting particles must collide with each other due to an increase in the temperature or any other factors that affect the rate of reaction before the products can be used. Solutions are often used because the reactant ions or molecules can move freely in solution and they are likely to collide with each other to form a product.
Therefore, the correct answer is option F