When is potential energy transformed into kinetic energy a) when an object at rest remains at rest b) when an object at rest is lifted to a higher elevation c) when an object in motion is stopped and put at rest d) when an object at rest is put into motion

Kinetic energy is when an object is in motion 
How I got my answer is really easy you simply just look at the answers and see which one says the object is in motion . Your answer would most likely be D

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .