Answer: The correct option is A.
Explanation:
Sound is a longitudinal wave. In longitudinal wave, the particles vibrate parallel to the direction of the propagation of the wave.
Sound wave consists of compression and rarefaction.
It needs medium to travel. It can travel in solid, liquid and gas. Denser the medium, more will be the speed of the sound.
Sound wave travels faster in solid in comparison to liquid.
In the given problem, when traveling from air to a solid then the speed of the sound wave will speed up.
Therefore, the correct answer is A.
