I think the answer is B! I hope that helps!!!!!
BRAINLY would be appreciated❤️
Answer:
<em>343 metres per second
</em>
<em>In dry air at 20 °C (68 °F), the speed of sound is 343 metres per second (about 767 mph, 1234 km/h or 1,125 ft/s).</em>
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Nonprportional is what I would think