If you see that a hot-air balloon is rising above the top of a hill, what is the top of the hill called? a. delta point b. distance system c. coordinate system d. reference point

If you see that a hot-air balloon is rising above the top of a hill,  the top of the hill is  called the reference point. Correct D The reference point is a point (object, place) used for comparison to determine if something is in motion,  assuming that the reference point is stationary, or not moving.

are there options? cause you ain’t. real specific

positive reinforcement? ?