Question

which phrase defines altitude?
how tightly molecules are packed
a column of air pushing on an area
the force pushing on an area or a surface
the height of a given point above sea level

Explanation:

Altitude refers to the vertical distance of a point above a reference level, typically sea level.

• "How tightly molecules are packed" refers to density.
• "A column of air pushing on an area" and "the force pushing on an area or a surface" relate to pressure concepts.

Answer:

the height of a given point above sea level