A rollercoaster goes down hill
a. kinetic energy is converted into potential energy
b. potential energy is converted into kinetic energy
c. electrical energy is converted into potential energy
d. potential energy is converted into electrical energy

a. potential energy is converted into kinetic energy

Explanation:

potential energy is the energy something has when it isn't in motion, as the roller coaster goes down hill (moves) the potential energy is turned into kinetic energy

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

with the invention of the automobile, the woman of the house could drive to the store and get groceries. women were also free to socialize more. during world war ii women were allowed to work in factories to the war effort and could drive to work or ride mass transit buses to their jobs.