19) Which of the following best illustrates the ceteris paribus assumption? * a)If the law requires people to wear seatbelts in order to reduce fatality rates, it may also cause people to drive faster. b)Chris notices that when economists discuss policy, they use the word "should" quite a lot, and they tend to disagree c)Felicia argues that since her company makes less profit when it limits its toxic pollution emissions, it must be true that pollution regulations are bad for everyone d)Caitlin notices that all other things being equal, her grades are higher the more time she spends studying