A questionnaire was sent to 34,000 randomly chosen individuals living in USA asking about their current and past smoking habits. For those who answered the questionnaire, they are tracked in the next 10 year for the death rate. Their data was pulled from the health record database so that if they died, the death is recorded with the diagnosis of the cause of the death. The death rates due to heart disease among the smokers and nonsmokers are then compared to see if smoking causes heart disease. What is the targeted population

The targeted population is USA residents who died of heart disease.

Step-by-step explanation:

According to this case, "the death rates due to heart disease among the smokers and nonsmokers are compared to see if smoking causes heart disease."  This implies that the study targets those USA residents who died of heart disease to find out if the cause of death can be traced to heart disease caused by smoking or not.  The main concentration for the study defines the targeted population.  It is this group of residents who died of heart disease that is the population of interest.  This means that the targeted population is a certain group of the population that share similar characteristics, especially death resulting from heart disease caused by smoking.

step-by-step explanation:

a and d