( The rapid motion and collisions of molecules ) with the walls of a container causes pressure.
Source; https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Pressure
Answer:
Gravitational Force.
Gravitation is the agent that gives weight to objects with mass and causes them to fall on the ground when dropped.
The correct option is C.
When glucose is stirred into water to form a solution, then glucose is the SOLUTE and water is the SOLVENT. A solute refers to a substance that is dissolved in a solvent. For instance, salt is the solute that is dissolved in salt solution. A solvent on the other hand refers to the liquid into which the solute was dissolved. For instance, in the case of salt solution, water is the solvent, because it is used to dissolve the salt.
Boyle's law of ideal gas: This law states that the volume of a gas is inversely proportional to its pressure at a constant temperature. Acc to this law we can write the relation of pressure and volume as:

That means:

From that equation we can calculate Volume of gas at a certain pressure:
P₁=Initial pressure
V₁=Initial volume
P₂=Final pressure
V₂= Final volume
Here P₁, initial pressure is given as 85.0 kPa
V₁, initial volume is given as 525 mL
P₂, final pressure is 65.0 kPa

so,
V_{2}=85\times 525\div 65
=686 mL
Volume of gas will be 686 mL.