Choose 3 research topics that would be best addressed through an observational study.
A. Does listening to loud music with headphones affect a person's
hearing?
B. Does second-hand smoke affect the health of pets?
C. Does a particular medication make seasonal allergy symptoms less
severe?
D. Does increasing the number of stoplights per mile on a road decrease the number
of car accidents on the road?
E. Does drinking sports drinks before and while playing a game of baseball increase
the number of runs scored?
F. Does a certain toothpaste prevent cavities in children better than another
toothpaste?