What aided the decline in population in the northeast and midwest in the 1970s apex?

C. Fewer job opportunities in the Northeast and Midwest
the 1970's experienced stagflation. The North East and the Midwest were hard hit.This led  to people moving to other areas,such as the sunbelt to look for job opportunities. Unemployment is a leading push factor in major migration patterns in the USA. The sunbelt was offering new opportunities,and thus populations moved into these areas.