Assertion
Sound travels faster in solids than gases
Reason
Solids possess greater density than gases
(A) Both Assertion and Reason ae correct explanation for Assertion
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(C) Assertion is correct but Reason is incorrect.
(D) Both Assertion Reasons are incorrect.

Hint:The sound waves are referred to as longitudinal waves that transfer from one point to the other through the medium and it does not travel through the vacuum space. It vibrates to transfer to the other places, the vacuum does not offer any medium for vibration.

Useful formula:
The formula of the velocity of the sound waves is given by
$v = \sqrt {\dfrac{E}{\rho }} $
Where $v$ is the velocity of the sound waves, $E$ is the elasticity of the medium and $\rho $ is the density of the medium.

Complete step by step solution:
The sound vibrates in a medium and moves to the other places. That medium can be either solid, liquid, and air. Among that the sound travels faster in the solid than the water and the air. Let us consider the formula of the velocity of the sound,
$v = \sqrt {\dfrac{E}{\rho }} $
Velocity is directly proportional to the elasticity. Since the solid possesses greater elasticity than the gases, the vibration of the sound waves is maximum in it. Hence the sound waves travel faster in the solid. Hence the assertion is correct. The solid is denser than the gases then the reason is also correct. But the velocity nature of the sound waves are only due to the elasticity and it decreases with the density.

Thus the option (B) is correct.

Note:Elastic behavior is due to the connection of the molecules, this facilitates the easier vibration of the sound waves to transfer from one molecule to another. The gas and the liquids are non-elastic and are loosely packed but solid is tightly packed.