A study compared a sample of Swedish people older than 75 who needed in-home assistance with a similar sample of Israel people. The people in the two samples received both informal assistance, provided by family and friends, and formal assistance, professionally provided. Although Sweden and Israel have equally well-funded and comprehensive systems for providing formal assistance, the study found that the people in the Swedish sample received more formal assistance, on average, than those in the Israeli sample.
Which of the following, if true, does most to explain the difference that the study?
【选项】In Israel, people older than 75 tend to live with their children, whereas in Sweden people of that age tend to live alone.