A study conducted in Norway suggests that ice-cream sales increases the rate of homicide (i.e. murder, or kill one perso

[answerhappygod]

A study conducted in Norway suggests that ice-cream sales
increases the rate of homicide (i.e. murder, or kill one person by
another). That is, if the sales of ice-cream is good in a
particular day, the chance of homicide to occur the day after would
increase.

a) [2 points] If you are asked to conduct the above study. Would
you prefer to perform it through a (i) randomized experiment, (ii)
case-control study, (iii) prospective study or (iv) retrospective
study?
b) [7 points] For each of the 3 studies you did not choose in part
(a), provide one reason on why the study is not preferred. (That
is, if you choose (i) in part (a), you should provide one reason
for why (ii) is not preferred, (iii) is not preferred and (iv) is
not preferred).
c) [3 points] Provide a possible confounding variable of the study.
Explain