Answer:
medium
Explanation:
<em>A sound </em><em>medium</em><em> is defined as channel through which sound can travel or be transmitted. </em>
Sound medium could be in the form gases, liquids, solids or plasmas. Space is made up of vacuum and therefore, has no medium within it. Hence, space cannot transmit sound in any form or allows sound to travel through it.
Pitch is the impression the listener gets of the <em>frequency</em> of the sound.
The speed of the sound is <em>not</em> related to its pitch/frequency.
If the speed and frequency were related, that would be a real problem. Bands, orchestras, and choirs could not exist ! All the instruments in the orchestra could play a note together, at the same time. But then the higher instruments ... the flute, trumpet, violins, high guitar strings and high piano keys ... would travel to you fast, and the lower instruments ... the trombone, tuba, double bass, bass drum, low guitar strings and the low piano keys ... would travel to you slow. They all played the note at the same time, but by the time you heard it, it would be all smeared out ... every instrument arriving at your ear at a different time !
B) equal in magnitude but opposite direction