The u. s. census bureau keeps records of different statistics that pertain to families. for example, in 2010, there were three million children who did not live with their parents. 54% of these children were:

Living with their grandparent(s)

Explanation:

There has been remarkable increase in the number of young people who live with their grandparents in the United States.  Over 71 percent of the children in the US are found in such homes in 2010, and these grandparents are said to be the ones that usually provide for the essential needs of these young citizens in their care. Economic downturn was identified to be one of the reason for this trend in these U.S homes.

the answer might be either a or c. can't be too sure , because i searched the web, but no valid answers came through.