According to Max well distribution of velocities:

CONCEPT:

• Basically Maxwell-Boltzmann distribution shows how the speed of molecules distributed for an ideal gas.
• It can be represented with the following graph

• If we draw Maxwell's curve between the number of particles and velocity, we can see that the curve first rises from zero to a maximum then again reaches zero.
• The total area under the graph represents the total no of molecules.

EXPLANATION:

• From the shape of the curve, it is clear that only a certain no of molecules achieves very high velocities and very low velocities.  Therefore option 2 is correct.
• The peak gives the no of molecules acquired high velocity and the flattened part gives the no of molecules that possess very low velocity.