By now, you know that sound is produced by vibrations. these vibrations can travel through solids, liquids, and gases, but not through
a) empty space
b) granite rock
c) living objects
d) the center of the earth

A) empty space

Explanation:

Sound waves are basically vibrations that travel through medium. If there is no medium for the vibrations to transfer from one place to another the sound wave will not travel.

Empty space or vacuum lacks any of the medium. Thus there is nothing through which vibrations can travel. This is the reason we can't hear anything if we go in space.

Rest all the options have a medium through which sound wave can travel.