Final answer:
The ears pop when the pressure in your inner and outer ear equalizes as you travel to a higher altitude, which corresponds to option C) Equalizes. This occurs because the external air pressure decreases, making it necessary for the pressure to equalize to maintain comfort and ear health.
Step-by-step explanation:
Your ears pop when traveling to a higher altitude because the pressure in your inner and outer ear equalizes. The correct answer to the question is C) Equalizes. At higher altitudes, the external air pressure decreases due to less atmospheric weight pressing down. As a result, the air pressure within your inner ear initially remains higher than the pressure outside, causing your ears to feel full or pressured.
When you yawn or swallow, the Eustachian tubes (which connect the middle ear to the back of the nose) open, allowing the pressure to equalize between the outside environment and your inner ear. Hence, the popping sensation is the sound of the Eustachian tubes opening, allowing the pressure to balance out.
This process of pressure equalization is essential for maintaining comfort and preventing potential injuries to the ear structures due to pressure differentials.