Answer: The atmospheric pressure decreases with altitude. This is because as we move higher above the earth's surface, there is less air above us and therefore less weight pushing down on us. Therefore, the correct answer is:
C. An altitude of 7 km above sea level
At an altitude of 7 km above sea level, a person would experience the least atmospheric pressure because they would be furthest from the earth's surface and there would be very little air above them. This is why the air pressure in the Earth's upper atmosphere is much lower than at the surface of the Earth.
Explanation: