which phrase describes density?○ height of a point above sea level○ force pushing on an area or a surface○…

Brief Explanations:

• "height of a point above sea level" describes elevation, not density.
• "force pushing on an area or a surface" describes pressure, not density.
• "amount of mass in a certain volume" is the standard definition of density, expressed mathematically as $\rho = \frac{m}{V}$ where $\rho$ is density, $m$ is mass, and $V$ is volume.
• "amount of matter an object contains" describes mass, not density.

Answer:

C. amount of mass in a certain volume