The repair of a double-strand break can be accomplished by ______________,which requires the Ku70/80 protein to _______________________.

A)nonhomologous end joining;catalyze blunt end ligation
B)nonhomologous end joining;bind to both ends of the break
C)homologous recombination;catalyze blunt end ligation
D)homologous recombination;bind to both ends of the break
E)none of the above