Question

A mountain climber reached an elevation of 1,600 feet above sea level. Which number line represents all locations below the climber’s elevation?

Answer 1

However, the surface of earth oceans, which we call sea level, is also the bottom ... VO2 max⁡ begins to decrease significantly above an altitude of 1600 m. ... during climbing to altitude also can have some negative effects on MP [3, 28]. ... number of central sleep apneas only at the highest reached altitude.

Answer 2

Below the climber's elevation = all values below 1,600 feet.

The answer is x < 1,600

Where x represents all possible values of locations below the climber's elevation.