DCA: north america DCB: south america ISP C: north american ISP ISP D: south american ISP A major fiber link between north and south america is cut, disr

DCA: north america DCB: south america ISP C: north american ISP ISP D: south american ISP A major fiber link between north and south america is cut, disrupting all connectivity between the two areas. "lose the link between DCs A and B": check. "lose the link from ISP D to DC A.": check. replace north and south america with any two disparate locations.