Which of the following statements about IS elements is not correct?

A) IS elements are responsible for the formation of Hfr strains of E. coli.
B) IS elements are less than 2,500 nucleotide pairs in size and contain only genes involved with promoting or regulating transcription.
C) IS elements are demarcated by short, inverted terminal repeats which have no role in the transpositional process.
D) IS elements are capable of creating target site duplications.
E) All of these are correct.