In a case-control study, two groups of the population are used, in which one group is kept as control, and the other is known as the experimental group that encounters with a specific disease or an outcome. With the help of this study, one can expose the groups to various or single outcomes.
In the given case, a study is done in which an advertisement on a ban on smoking is encouraged by the non-smokers at the alcohol sale points but not by smokers, in the process a random digit dialing method was used. This random digit dialing method is an illustration of a case-control study, in which the survey of the individuals is done regarding the ban on smoking.
One adaptation that is unique to marine mammals is they nurse their young.. The correct option among all the options that are given in the question is the fourth option or the last option or option "d". I hope that this is the answer that you were looking for and the answer has come to your desired help.