If the number of particles of gas within a container stays constant, and the volume of the container is reduced, then Question 10 options:?

A) false
The effect of the change of the volume of the container is negligible to the surroundings. The pressure outside of the container remains unchanged.

B) false
When the volume of the container is reduced, the particles of the gas become denser. The frequency of the collisions between the particles of gas and the walls of the container becomes higher. This leads to the rise of pressure within the container.

C) true
Refer to the explanation in option B.

D. false
Refer to the explanation in option B.

The answer: C) the pressure within the container will rise.

Boyle's Law: Volume is indirectly proportional to pressure 

or...

P_1 * V_1 = P_2 * V_2

Id V_2  < V_1 then P_2 > P_1

At constant temperature and given Pressure and Volume, we have 
PV = constant

Now, if the Volume reduces then Pressure has to increase. So answer is C