I believe the answer is: Replication
During a replication, Researchers would repeat the research that conducted in the past, but being done with different situations or different type of subjects. The purpose of such research is to determine if the finding on the previous research would be applicable under different circumstances.
Mostly some elderlies like to live in thier own homes not a nursing home and also they would like to live in a planned retirement community too so both a and c is the answer.really hope this helps?
Answer:
population density
Explanation:
Because many people travel from rural areas to urban areas in search of greener pastures therefore making the population rise