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.

answer: i pick a

explanation:

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this