If a sound is refracted away from the surface of the earth, this indicates that the a. air is cooler than the ground. b. wind is blowing in the direction of the sound. c. ground is cooling faster than the air. d. air has high humidity.

The correct answer is option A, that is, air is cooler than the ground.

Explanation:

Refraction refers to a phenomenon in which there is a modification in the direction of propagation of any wave as a consequence of its mediating at distinct velocities and at distinct points along the wavefront.  In case, when a sound from s source is refracted away from the Earth's surface, there is an indication that the air present above is cooler in comparison to the ground making the sound to refract towards the less dense medium.

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